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Extended N-Arylsulfonylindoles as 5-HT6 Receptor Antagonists: Design, Synthesis & Biological Evaluation Gonzalo Vera 1,† , Carlos F. Lagos 2,3,† , Sebastián Almendras 1 , Dan Hebel 1 , Francisco Flores 1 , Gissella Valle-Corvalán 4 , C. David Pessoa-Mahana 1 , Jaime Mella-Raipán 4 , Rodrigo Montecinos 5 and Gonzalo Recabarren-Gajardo 1, * 1

2 3 4

5

* †

Departamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Avda. Vicuña Mackenna 4860, Macul 7820436, Santiago, Chile; [email protected] (G.V.); [email protected] (S.A.); [email protected] (D.H.); [email protected] (F.F.); [email protected] (C.D.P-M.) Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Lira 85, 5th Floor, Santiago 8330074, Chile; [email protected] Facultad de Ciencia, Universidad San Sebastián, Lota 2465, Providencia 7510157, Santiago, Chile Instituto de Química y Bioquímica, Facultad de Ciencias, Universidad de Valparaíso, Casilla 5030, Av. Gran Bretaña 1111, Playa Ancha, Valparaíso 2360102, Chile; [email protected] (G.V.-C.); [email protected] (J.M.-R.) Departamento de Química-Física, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Avda. Vicuña Mackenna 4860, Macul 7820436, Santiago, Chile; [email protected] Correspondence: [email protected]; Tel.: +56-223-541-418 These authors contributed equally to this work.

Academic Editor: Jean Jacques Vanden Eynde Received: 3 May 2016; Accepted: 8 August 2016; Published: 16 August 2016

Abstract: Based on a known pharmacophore model for 5-HT6 receptor antagonists, a series of novel extended derivatives of the N-arylsulfonyindole scaffold were designed and identified as a new class of 5-HT6 receptor modulators. Eight of the compounds exhibited moderate to high binding affinities and displayed antagonist profile in 5-HT6 receptor functional assays. Compounds 2-(4-(2-methoxyphenyl) piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4b), 1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)-2(4-(2-methoxyphenyl)piperazin-1-yl)ethanol (4g) and 2-(4-(2-methoxyphenyl)piperazin-1-yl)-1-(1(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanol (4j) showed the best binding affinity (4b pKi = 7.87; 4g pKi = 7.73; 4j pKi = 7.83). Additionally, compound 4j was identified as a highly potent antagonist (IC50 = 32 nM) in calcium mobilisation functional assay. Keywords: arylsulfonylindole; 5-HT6 receptor antagonists; binding affinity; arylpiperazines

1. Introduction The human receptor of serotonin (5-HT) subtype 6 (5-HT6 R), belongs to the class-A seven transmembrane G protein-coupled receptor family [1–3]. 5-HT6 R is positively coupled to Gαs subunits, thereby stimulating adenylate cyclase, and its expression is restricted almost exclusively to limbic and cortical regions of the central nervous system [4]. Evidence that 5-HT6 R shows high affinity for both typical and atypical antipsychotic drugs, as well as some other psychotropic agents, and that these drugs behave as antagonists of 5-HT6 R, triggered great interest in establishing the role of 5-HT6 R in both physiological and pathological conditions [5]. Blockade of the 5-HT6 R function increases cholinergic and glutamatergic neurotransmission, and improves cognition parameters in a number of animal models of cognitive deficits, suggesting that 5-HT6 R may have therapeutic utility in the treatment of various neurological and psychiatric disorders such as anxiety, depression and epilepsy [6–8]. In addition, previous studies demonstrated that 5-HT6 R has a major role in obesity, thus Molecules 2016, 21, 1070; doi:10.3390/molecules21081070

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boosting the search novel selective [9]. 2-Methyl analog of 5-HT was 5-HT among novel selective 5-HTfor 6R antagonists [9]. 5-HT 2-Methyl analog of 5-HT was among the first selective 6R 6 R antagonists the first selective 5-HT R agonists reported [10]. LSD and Clozapine are established standard 5-HT agonists reported [10].6 LSD and Clozapine are established standard 5-HT6R antagonists that have 6R antagonists have beenand used as radioligand andassays, controlrespectively in functional assays, respectively [1,11]. been used asthat radioligand control in functional [1,11]. Several potent indole Several potent indole and N-arylsulfonylindole bindtowith high affinity to also 5-HTreported R and N-arylsulfonylindole derivatives that bindderivatives with high that affinity 5-HT 6R have been 6 have been also reported in the literature (Figure 1) [12–16]. in the literature (Figure 1) [12–16].

Figure 1. 1. Structure and affinities affinities of of 5-HT 5-HT6R ligands. Agonists: 5-HT and 2-Me 5-HT, Antagonists: LSD, Figure Structure and 6 R ligands. Agonists: 5-HT and 2-Me 5-HT, Antagonists: LSD, Clozapine and N-arylsulfonylindole I to VI. (Ki == inhibitory constant from radioligand binding assays, Clozapine and N-arylsulfonylindole I to VI. (K i inhibitory constant from radioligand binding assays, see Section 4.5). see Section 4.5).

All reported antagonists I–VI share a common pharmacophore consisting of basic ionizable amine All reported antagonists I–VI share a common pharmacophore consisting of basic ionizable amine functionality, a sulfonamide moiety as hydrogen bond acceptor group connected to a hydrophobic functionality, a sulfonamide moiety as hydrogen bond acceptor group connected to a hydrophobic indole site and an aromatic ring (AR) [17]. Accordingly, a large majority of these compounds are basic. indole site and an aromatic ring (AR) [17]. Accordingly, a large majority of these compounds The large majority of these 5-HT6R modulators have a basic nitrogen which enables an ionic interaction are basic. The large majority of these 5-HT6 R modulators have a basic nitrogen which enables an with residue D106 (3.32). It has not been convincingly demonstrated the need for a basic side chain for ionic interaction with residue D106 (3.32). It has not been convincingly demonstrated the need effective interaction with the 5-HT6 receptor. In this sense, few authors have reported non-basic for a basic side chain for effective interaction with the 5-HT6 receptor. In this sense, few authors compounds displaying 5-HT6R activity [18,19]. As part of our studies focused on the development of have reported non-basic compounds displaying 5-HT6 R activity [18,19]. As part of our studies multimodal modulators of serotonergic system, we are interested in evaluating the 5-HT6R affinity of focused on the development of multimodal modulators of serotonergic system, we are interested less basic analogs of I–VI and exploring the steric limits of a three-dimensional pharmacophore model in evaluating the 5-HT6 R affinity of less basic analogs of I–VI and exploring the steric limits of a for 5-HT6R antagonists. Herein, we report the design, synthesis, and preliminary pharmacological three-dimensional pharmacophore model for 5-HT6 R antagonists. Herein, we report the design, characterization of two series of weakly basic extended N-arylsulfonylindole derivatives targeting synthesis, and preliminary pharmacological characterization of two series of weakly basic extended 5-HT6R. N-arylsulfonylindole derivatives targeting 5-HT6 R. 2. Results 2. Results 2.1. Molecular Molecular Modeling Modeling and and Design Design 2.1. Active antagonist VIVI plus Clozapine were docked within the binding site ofsite a model Active antagonistligands ligandsI to I to plus Clozapine were docked within the binding of a of the human 5-HT 6R constructed using the human β2 adrenergic receptor (β2-AR) as a template [20]. As model of the human 5-HT6 R constructed using the human β2 adrenergic receptor (β2 -AR) as a shown in Figure 2A, the predicted binding mode for Clozapine and arylsulfonyl derivatives occupies template [20]. As shown in Figure 2A, the predicted binding mode for Clozapine and I–VI arylsulfonyl the same region within the 6R. The tricyclic system benzene rings of Clozapine which orients derivatives I–VI occupies the5-HT same region within the 5-HT6 R. The tricyclic system benzene rings of perpendicular to the membrane plane, superpose with those the indole Clozapine which orients perpendicular to the membrane plane,from superpose with and thosesulfonyl-attached from the indole rings in arylsulfonylindoles derivatives, a binding mode similar to the model proposed by model Selent and sulfonyl-attached rings in arylsulfonylindoles derivatives, a binding mode similar to the et al. [21].byArylsulfonylindoles are predicted to are bind preferentially the region delimited by proposed Selent et al. [21]. Arylsulfonylindoles predicted to bindwithin preferentially within the region transmembrane helices (TMH) 3–7. Ligands are predicted to bind with the phenyl part of the indole delimited by transmembrane helices (TMH) 3–7. Ligands are predicted to bind with the phenyl part of nucleus towards thetowards inner partthe of inner the receptor the hydrophobic pocket delimitedpocket by the side-chains the indole nucleus part ofwithin the receptor within the hydrophobic delimited of V107 (3.33), A192 (5.42), T196 (5.46), W281 (6.48), and F285 (6.52), whereas the sulfonyl moiety by the side-chains of V107 (3.33), A192 (5.42), T196 (5.46), W281 (6.48), and F285 (6.52), whereas the establishes contacts with either S193 (5.43) or N288 (6.55). The aromatic ring pending over the sulfonyl sulfonyl moiety establishes contacts with either S193 (5.43) or N288 (6.55). The aromatic ring pending groups is oriented towards the solvent and interacts with residues on the ECL2 such as L182, A184 and other hydrophobic residues such as V189 (5.39) and F284 (6.51). This obtained binding mode, resembles the pharmacophore hypotheses previously proposed by López-Rodríguez et al. [22], but

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over the sulfonyl groups is oriented towards the solvent and interacts with residues on the ECL2 such as L182, A184 and other hydrophobic residues such as V189 (5.39) and F284 (6.51). This obtained binding mode, resembles the pharmacophore hypotheses previously proposed by López-Rodríguez et al. [22], but differs from other authors that have reported either an inverse orientation of the indole core Molecules 2016, 21, 1070 3 of 33 for arylsulfonyltryptamines such as the binding mode as reported by Pullagurla et al, or different differs from authorspocket that have reported eitherreported an inverse by orientation for (I) [23,24]. positioning within theother binding such as that Dukatofettheal.indole for core MS-245 arylsulfonyltryptamines the binding mode as reported by Pullagurla et al, or different positioning The differences may arise fromsuch theasuse of rhodopsin structure as a template for 5-HT R 6 modelling in within the binding pocket such as that reported by Dukat et al. for MS-245 (I) [23,24]. The differences the latter cases. may arise from the use of rhodopsin structure as a template for 5-HT6R modelling in the latter cases.

Figure 2. Modeling of 5-HT6R interactions with active antagonists. (A) Superposition of FRED-predicted

Figure 2. Modeling of 5-HT with active antagonists. (A) Superposition of FRED-predicted 6 R interactions binding modes for active antagonists arylsulfonylindoles I–VI and Clozapine in the binding pocket of 5-HTfor 6R, delimited by transmembrane helices (TMH) 3–6. Different protein residues conformers and binding modes active antagonists arylsulfonylindoles I–VI and Clozapine in the binding pocket ligands are shown with carbon atoms in white and green color respectively, while Clozapine is shown of 5-HT6 R, delimited by transmembrane helices (TMH) 3–6. Different protein residues conformers with yellow carbon atoms (B) Alternative hydrophobic pockets in the TMH3-TMH4-TMH5 and and ligands are shown with carbon white and green color respectively, while Clozapine is TMH2-TMH3-TMH7 regions of atoms the 5-HTin 6R. shown with yellow carbon atoms (B) Alternative hydrophobic pockets in the TMH3-TMH4-TMH5 and In our 5-HT 6R model, the predicted binding mode of the active arylsulfonylindoles highlights TMH2-TMH3-TMH7 regions of the 5-HT6 R.

two additional pockets that were explored in search for putative fragments (Figure 2B). Docking of the Maybridge rule of 3 (Ro3) fragments database (2500 diverse compounds) was performed and the top 500 scored molecules were selected for further analysis. Pocket 1 was explored, and the Chemgauss4 In our 5-HT 6 R model, the predicted binding mode of the active arylsulfonylindoles highlights scores ranged from −11.33 to −6.45 for the top 500 scored compounds (Figure 3A). The Chemgauss4 two additional pockets that were explored in search for putative fragments (Figure 2B). Docking of scores ranged from −16.92 to −9.08 for the top 500 scored compounds on pocket 2 allowing us to the Maybridge rule of 3identify (Ro3)arylpiperazines fragmentsand database diverse compounds) performed and unsurprisingly morpholine(2500 as putative fragments that might fill awas secondary hydrophobic pocket delimited by TMHs 2, 3 and 7 (Figure 3B), where they are predicted to interact the top 500 scored molecules were selected for further analysis. Pocket 1 was explored, and the with residues A83(2.61), W102(3.28), F302(7.35), D303(7.36) and W307(7.40). Therefore, we reasoned Chemgauss4that scores ranged from −11.33 to −6.45 for the top 500 scored compounds (Figure 3A). The extending the classic N-arylsulfonylindole nucleus with these moieties could provide novel 5-HT6R Chemgauss4modulators scores ranged −16.92 9.08 for the top 500was scored with highfrom binding affinity.to The−design of the compounds aimed compounds at exploring the on pocket 2 of the structural pharmacophore framework model already proposed for N-arylsulfonylindole allowing us limits to unsurprisingly identify arylpiperazines and morpholine as putative fragments that and other classes of 5-HT6R ligands (Figure 3C) [25,26]. Superposition of docking positions obtained might fill a secondary hydrophobic pocket delimited by TMHs 2, 3 and 7 (Figure 3B), where they for the central core indole sulfonamide and fragments for pockets 1 and 2 were then superimposed are predictedtoto interact residues A83(2.61), D303(7.36) and W307(7.40). determine thewith common fragments and tolerant W102(3.28), regions allowingF302(7.35), for merging the chemical moieties (Figure 3D). Superposition of fragment and the structure of carazolol present in the Therefore, we reasoned that extending thedocking classicresults N-arylsulfonylindole nucleus with these moieties β2-adrenergic receptor template also suggest that the linker present can be used to connect both could provide novel 5-HT6 R modulators with high binding affinity. The design of the compounds was

aimed at exploring the limits of the structural pharmacophore framework model already proposed for N-arylsulfonylindole and other classes of 5-HT6 R ligands (Figure 3C) [25,26]. Superposition of docking positions obtained for the central core indole sulfonamide and fragments for pockets 1 and 2 were then superimposed to determine the common fragments and tolerant regions allowing for merging the chemical moieties (Figure 3D). Superposition of fragment docking results and the structure of

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carazolol present in the β2-adrenergic receptor template also suggest that the linker present can be used fragments. to connectInterestingly, both fragments. Interestingly, the close and β-blocker and pindolol the close β-blocker propanolol pindololpropanolol display antagonist activity display on antagonist activity on other 5-HT receptors [27,28]. other 5-HT receptors [27,28].

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fragments. Interestingly, the close β-blocker propanolol and pindolol display antagonist activity on other 5-HT receptors [27,28].

Figure 3. Structure-based design of novel N-arylsulfonylindole derivatives targeting the 5-HT6R. (A)

Figure 3. Structure-based design of novel N-arylsulfonylindole derivatives targeting the 5-HT6 R. Chemgauss4 scored ranked solution for the Maybridge Ro3 library in pockets 1 and 2 sites in 5-HT6R (A) Chemgauss4 scored ranked solution for the Maybridge Ro3 library in pockets 1 and 2 sites in 5-HT6 R from FRED screening; (B) Superposition of FRED-predicted binding modes for active 5-HT6R antagonist from FRED screening; (B) Superposition of FRED-predicted binding modes for active 5-HT6 R antagonist MS-245 (carbon atoms in magenta) and top ranked compounds from the Maybridge Ro3 database; MS-245 in magenta) and top ranked compounds from the of Maybridge Ro3 target database; (C)(carbon Structuralatoms pharmacophore framework model and schematic representation the synthesized (C) Structural pharmacophore framework model and schematic representation of the synthesized compounds; (D) Prototype designed ligands using a fragment-based strategy in the context of receptor targetstructure, compounds; Prototype ligands using a fragment-based strategy in the context of which(D) satisfy the 5-HTdesigned 6R antagonists pharmacophore framework model. Figure 3. Structure-based design of novel N-arylsulfonylindole derivatives targeting the 5-HT6R. (A) receptor structure, which satisfy the 5-HT R antagonists pharmacophore framework model. 6 2.2. Synthesis Chemgauss4 scored ranked solution for the Maybridge Ro3 library in pockets 1 and 2 sites in 5-HT6R from FRED screening; (B) Superposition of FRED-predicted binding modes for active 5-HT6R antagonist

2.2. Synthesis MS-245 (carbon series atoms inofmagenta) top ranked from the Maybridge database; Synthesis of the novel ligandsand (3a–m andcompounds 4a–m) was performed asRo3 summarized in Scheme 1. (C) Structural pharmacophore framework model and schematic representation of the synthesized target

We first synthesized 3-(2-bromoacetyl)indole 1 using according to the method reported by Bergman and Yang compounds; (D)series Prototypeof designed ligands (3a–m a fragment-based strategy in theperformed context of receptoras summarized in Synthesis of the novel ligands and 4a–m) was [29,30]. Briefly,structure, acylation was performed in a two-step sequence, starting which satisfy the 5-HT R antagonists pharmacophore framework model. from a premixed solution of Scheme 1. We first synthesized 3-(2-bromoacetyl)indole 1 according to the method reported by commercial indole and anhydrous zinc chloride, to which was quickly added methyl magnesium 2.2. Synthesis Bergman and Yang [29,30]. Briefly, acylation was performed in a two-step sequence, starting from a bromide to provide the corresponding magnesium salt. This salt undergoes an in situ transmetallation Synthesis of the novel series of ligands (3a–m and 4a–m) was performed summarized in Scheme premixed solution of commercial indole and anhydrous zinc chloride, to which was1.bromoacetyl quickly added reaction with the zinc chloride previously added. Then, the zinc saltaswas acylated with We first synthesized 3-(2-bromoacetyl)indole 1 according to the method reported by Bergman and Yang methyl magnesium bromide to provide the corresponding magnesium salt. This salt undergoes chloride under inert atmosphere afford bromoacetylindole 1 in a good as solution compared with thean in [29,30]. Briefly, acylation wastoperformed in a two-step sequence, starting from a yield premixed of situ transmetallation reaction with the zinc chloride previously added. Then, the zinc salt was acylated commercial indole and anhydrous zinc chloride, to which was quickly added methyl magnesium literature [29]. bromide to provide the corresponding magnesium salt. salt undergoes an in situ transmetallation with bromoacetyl chloride under inert atmosphere toThis afford bromoacetylindole 1 in a good yield as reaction with the zinc chloride previously added. Then, the zinc salt was acylated with bromoacetyl compared withchloride the literature [29]. under inert atmosphere to afford bromoacetylindole 1 in a good yield as compared with the 6

literature [29].

Scheme 1. Synthesis of derivatives 3a–m and 4a–m. Reagents and conditions: (a) (i) anhydrous ZnCl2, , CH3MgBr, RT, of 2 h; (ii) BrCH 2COCl, RT, Reagents 12 h. (b) 2Cl, (a) Et3(i) N,anhydrous DMAP, ZnCl CH22,Cl2, RT, 5 h. dry CH2Cl2Scheme 1. Synthesis derivatives 3a–m and 4a–m. andArSO conditions: Scheme 1. Synthesis of2or 3a–m and 4a–m.12Reagents conditions: (a) (i) anhydrous ZnCl2 , , derivatives CH 3MgBr, RT, 2 h;K (ii) BrCH 2COCl, RT,RT, h.overnight. (b) ArSOand 2Cl, Et 3N,NaBH DMAP,4,CH 2Cl2, RT,RT, 5 h. 3 h. dry CH2Cl (c) arylpiperazines morpholine, 2CO 3, acetone, (d) MeOH, arylpiperazines K2CO 3, acetone, (d) NaBHCl, RT,DMAP, 3 h. dry CH2 Cl2 , CH(c)3 MgBr, RT, 2orh;morpholine, (ii) BrCH RT,RT, 12overnight. h. (b) ArSO Et3 N, CH2 Cl2 , RT, 5 h. 2 COCl, 2 4, MeOH, (c) arylpiperazines or morpholine, K2 CO3 , acetone, RT, overnight. (d) NaBH4 , MeOH, RT, 3 h.

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The The bromoacetylindole bromoacetylindole 11 previously previously obtained obtained was was further reacted with appropriate aromatic aromatic sulfonyl sulfonyl chlorides chlorides under under basic basic conditions conditions to to afford afford the corresponding corresponding N-arylsulfonyl-3N-arylsulfonyl-3bromoacetylindoles 2a–g with modest to good yields [31]. The prepared haloketones The prepared haloketones were were subjected subjected to to bromide bromide displacement displacement in in basic basic medium medium at at room temperature respective functionalized functionalized temperature with with various various arylpiperazines arylpiperazines or or morpholine morpholine to to obtain the respective ethanones excellent yields except except compounds exhibited a ethanones 3a–m 3a–m in very good to excellent compounds 3a 3a and and 3k, which exhibited moderate moderate yield yield (Table 1) [32]. Ketones obtained after the N-alkylation N-alkylation reaction reaction above were subsequently reduced with sodium borohydride in methanol to obtain the corresponding alcohols 4a–m4a–m (Table 1). The reduced with sodium borohydride in methanol to obtain the corresponding alcohols (Table 1). 1 1 structures of the novel compounds were confirmed The structures of the novel compounds were confirmedthrough throughspectroscopic spectroscopicmethods. methods. H-NMR H-NMR and and 13 13C-NMR C-NMRchemical chemical shifts shifts and and physical physical data data are are gathered gathered in in Section Section 4.3. Table derivatives aa. Table 1. Yield and melting point data of new N-arylsulfonylindole derivatives Ar

Ar

N

N

N

N

Z

O

N

Z

N S

O

Z

N

O O

S

N

O O

R

For 3a-h and 4a-h

S

O

R

For 3i-k and 4i-k

For 3l-m and 4l-m

Code Z R Ar d Yield b (%) m.p. (°C) ◦ Z R m.p. ( C) Ar Yield b (%) 3a CO 4-Me 2-Py 46 75–76 3a CO 4-Me 2-Py 46 75–76 3b CO 4-Me 2-MeOPh 66 132–134 3b CO 4-Me 2-MeOPh 66 132–134 CO 4-Me 2-Pyrim 91 91 133–134 3c 3c CO 4-Me 2-Pyrim 133–134 CO 4-Cl 2-Pyrim 89 89 168–169 3d 3d CO 4-Cl 2-Pyrim 168–169 3e 3e CO 4-F 2-Pyrim 77 145–146 CO 4-F 2-Pyrim 77 145–146 3f CO 4-I 2-Py 179–180 3f CO 4-I 2-Py 93 93 179–180 3g CO 4-I 2-MeOPh 98 182–183 CO 4-I 2-MeOPh 98 96 182–183 3h 3g CO 4-I 2-Pyrim 184–185 CO 4-I2-Pyrim 96 86 184–18576–77 3i 3h CO 2-Py 3j 3i CO 2-MeOPh CO -2-Py 86 74 76–77 74–75 3k 3j CO 2-Pyrim 46 CO 2-MeOPh 74 74–75 88–89 3l CO 4-OMe 81 nd c 3k CO 2-Pyrim 46 88–89 3m CO 3,5-diF 91 nd c c 3l CO 4-OMe 81 nd CHOH 4-Me 2-Py 98 72–74 4a CO 3,5-diF 91 99 nd c 86–87 CHOH 4-Me 2-MeOPh 4b 3m 4c 4a CHOH 4-Me 2-Pyrim CHOH 4-Me 2-Py 98 68 72–74 81–82 4d CHOH 4-Cl 2-Pyrim 75 4b CHOH 4-Me 2-MeOPh 99 86–87 76–77 4e CHOH 4-F 2-Pyrim 69 72–73 CHOH 4-Me 2-Pyrim 68 56 81–82157–158 4f 4c CHOH 4-I 2-Py CHOH 4-Cl 2-Pyrim 75 62 76–77109–110 4g 4d CHOH 4-I 2-MeOPh 4h 4e CHOH 4-I 2-Pyrim 67 CHOH 4-F 2-Pyrim 69 72–73171–172 4i 4f CHOH 2-Py 72 CHOH 4-I 2-Py 56 157–15880–81 4j CHOH 2-MeOPh 61 89–90 4g CHOH 4-I2-MeOPh 62 65 109–11082–83 4k CHOH 2-Pyrim CHOH 4-I 2-Pyrim 67 53 171–172 4l 4h CHOH 4-OMePh 149–152 4m 4i CHOH 3,5-diFPh CHOH 2-Py72 66 80–81 nd c a The products were b Yields refer to pure 4j characterized CHOH by IR-and NMR 2-MeOPh spectroscopy and 61 physical data.89–90 c Compounds in gel state. d Ph = Phenyl; Py = Pyridine; Pyrim = Pyrimidine. isolated products. 4k CHOH 2-Pyrim 65 82–83 4l CHOH 4-OMePh 53 149–152 4m CHOH 3,5-diFPh 66 nd c d

Code

The products were characterized by IR and NMR spectroscopy and physical data. b Yields refer to pure isolated products. c Compounds in gel state. d Ph = Phenyl; Py = Pyridine; Pyrim = Pyrimidine.

a

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2.3. Pharmacology Synthesized N-arylsulfonylindole derivatives were tested in a standard radioligand competition binding assay, using membranes of HEK-293 cells expressing a recombinant recombinant human human 5-HT 5-HT66 receptor. receptor. The compounds were assayed as free bases at eight concentrations in triplicate to obtain the dosecompounds were assayed as free bases at eight concentrations in triplicate to obtain the response curves, determine IC50 values and calculate Ki values (Table(Table 2). 2). dose-response curves, determine IC50 values and calculate Ki values Table 2. 5-HT66R binding affinity results for new N-arylsulfonylindole derivatives aa. Table 2. Ar

Ar

N

N

N

N

Z

S

N

Z

N O

O

Z

N

O O

S

N

O O

S

R

For 3a-h and 4a-h

O

R

For 3i-k and 4i-k

For 3l-m and 4l-m

Code Z R Ar c pKi b Code Z R Ar pKi b Z R Ar c Code Z R Ar pKi b pKi b 3a 4a CO 4-Me 2-Py 5.75 ± 0.14 CHOH 4-Me 2-Py 6.32 ± 0.19 3a CO 4-Me 2-Py 5.75 ± 0.14 4a CHOH 4-Me 2-Py 6.32 ± 0.19 3b 4b CO 4-Me 2-MeOPh 4.97 ± 0.18 CHOH 4-Me 2-MeOPh 7.87 ± 0.15 3b CO 4-Me 2-MeOPh 4.97 ± 0.18 4b CHOH 4-Me 2-MeOPh 7.87 ± 0.15 4c CO 4-Me 2-Pyrim 6.11 6.11±±0.14 0.14 CHOH 4-Me 2-Pyrim 6.07±±0.15 0.15 3c3c CO 4-Me 2-Pyrim 4c CHOH 4-Me 2-Pyrim 6.07 3d CO 4-Cl 2-Pyrim 4d CHOH 4-Cl 2-Pyrim 5.43 3d 4d CO 4-Cl 2-Pyrim 5.07 5.07±±0.14 0.14 CHOH 4-Cl 2-Pyrim 5.43±±0.20 0.20 3e3e CO 4-F 2-Pyrim 4e CHOH 4-F 2-Pyrim 5.66 4e CO 4-F 2-Pyrim 4.72 4.72±±0.14 0.14 CHOH 4-F 2-Pyrim 5.66±±0.20 0.20 3f CO 4-I 2-Py 6.10 ± 0.08 4f CHOH 4-I 2-Py 6.43 ± 0.15 3f 4f CO 4-I 2-Py 6.10 ± 0.08 CHOH 4-I 2-Py 6.43 ± 0.15 3g CO 4-I 2-MeOPh 5.72 ± 0.40 4g CHOH 4-I 2-MeOPh 7.73 ± 0.09 3g 4g CO 4-I 2-MeOPh 5.72 ± 0.40 CHOH 4-I 2-MeOPh 7.73 ± 0.09 3h CO 4-I 2-Pyrim 6.38 ± 0.23 4h CHOH 4-I 2-Pyrim 6.21 ± 0.21 3i3h CO 2-Py 5.91 4i CHOH 2-Py 6.83 4h CO 4-I 2-Pyrim 6.38±±0.14 0.23 CHOH 4-I2-Pyrim 6.21±±0.14 0.21 3j3i CO 2-MeOPh 5.90 4j CHOH 2-MeOPh 7.83 4i CO -2-Py 5.91±±0.15 0.14 CHOH -2-Py 6.83±±0.14 0.14 3k CO 2-Pyrim 5.85 ± 0.20 4k CHOH 2-Pyrim 6.22 ± 0.19 3j 4j CO 2-MeOPh 5.90 ± 0.15 CHOH 2-MeOPh 7.83 ± 0.14 3l CO 4-OMe – 6.35 ± 0.10 4l CHOH 4-OMe – 6.05 ± 0.07 3k 4k CO 2-Pyrim 5.85±±0.11 0.20 CHOH 2-Pyrim 6.22±±0.15 0.19 3m CO 3,5-diF – 4.65 4m CHOH 3,5-diF – 5.12 Clozapine -– 7.92 1 -– 8.70 ±[1]0.07 3l 4l CO 4-OMe 6.35±±0.13 0.10 CHOH 4-OMe 6.05 5-HT 7.12 [10] 3m 4m CO 3,5-diF – 4.65 ± 0.11 CHOH 3,5-diF – 5.12 ± 0.15 a Displacement of [125 I]-SB-258585 bound to cloned 5-HT human receptors stably expressed in HEK-293 cells. 6 Clozapine 1 7.92 ± 0.13 8.70 [1] b IC values (not shown) were determined in triplicate and K values were calculated using the Cheng-Prusoff i 5-HT50 7.12 [10] Code

equation [33]. Ki = inhibitory constant from radioligand binding assays. In this assay, the IC50 value of clozapine

125I]-SB-258585 bound Displacement cloned Py 5-HT 6 humanPyrim receptors stably expressed in HEK-293 was 12.4 nM; Kof nM, pKi = 7.92. c Phto = Phenyl; = Pyridine; = Pyrimidine. i = [11.9 cells. b IC50 values (not shown) were determined in triplicate and Ki values were calculated using the Cheng-Prusoff equation [33].displayed Ki = inhibitory constant from radioligand binding assays. In assay, All tested compounds inhibition of [125 I]-SB-258585 binding to this 5-HT 6 R [34]. 50 value of clozapine was 12.4 nM; Ki = 11.9 nM, pKi = 7.92. c Ph = Phenyl; Py = Pyridine; Pyrim = the IC Compounds 4b, 4f, 4g, 4i, and 4j were the most potent compounds with pKi values of 7.87, 6.43, 7.73, Pyrimidine. 6.83 and 7.83, respectively. In our hands, the standard 5-HT R antagonist clozapine displayed a a

6

pKi value of 7.92 (IC50 value of 12.4 nM). All tested compounds displayed inhibition of [125I]-SB-258585 binding to 5-HT6R [34]. Compounds The most potent alcohol compounds 4a, 4b and 4f–4k from the series were further evaluated 4b, 4f, 4g, 4i, and 4j were the most potent compounds with pKi values of 7.87, 6.43, 7.73, 6.83 and 7.83, for their functional properties in an intracellular calcium mobilization assay (Table 3). The protocol respectively. In our hands, the standard 5-HT6R antagonist clozapine displayed a pKi value of 7.92 consisted of the addition of test compounds, followed by the addition of known selective 5-HT6 R (IC50 value of 12.4 nM). agonist 2-Me 5-HT. Upon ligand binding to the receptor, Ca2+ is released into the cytoplasm of the cell. The most potent alcohol compounds 4a, 4b and 4f–4k from the series were further evaluated for A diminished Ca2+ mobilization in response to the addition of the test compound would indicate its their functional properties in an intracellular calcium mobilization assay (Table 3). The protocol antagonist activity [35]. consisted of the addition of test compounds, followed by the addition of known selective 5-HT6R All ligands evaluated showed an antagonist profile, since there was no response upon addition of agonist 2-Me 5-HT. Upon ligand binding to the receptor, Ca2+ is released into the cytoplasm of the test compounds, but a2+decrease in the effects following the addition of 2-Me 5-HT. We also determined cell. A diminished Ca mobilization in response to the addition of the test compound would indicate the IC50 value of the standard antagonist clozapine. In this assay the most potent compound was 4j its antagonist activity [35]. which had an IC50 value of 32 nM. All ligands evaluated showed an antagonist profile, since there was no response upon addition of test compounds, but a decrease in the effects following the addition of 2-Me 5-HT. We also determined the IC50 value of the standard antagonist clozapine. In this assay the most potent compound was 4j which had an IC50 value of 32 nM.

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7 of 33 a. a . Table 3. 3. Antagonism calciummobilization mobilization Table Antagonismof ofintracellular intracellular calcium

Code R R 4a 4-Me 4a 4-Me 4b 4-Me 4b 4-Me4-I 4f 4f 4-I 4-I 4g 4g 4-I 4h 4-I 4h 4-I 4i 4i 4j 4j - 4k 4k - Clozapine Clozapine - Code

Ar d IC50 (nM) b Ar d 2-Py 783 2-MeOPh2-Py nd c 2-Py2-MeOPh 24,600 2-MeOPh2-Py 204 2-MeOPh 2-Pyrim 75 2-Pyrim 2-Py 399 2-Py 2-MeOPh 2-MeOPh 32 2-Pyrim 2-Pyrim 688 15.9 -

IC50 (nM) b 783 nd c 24,600 204 75 399 32 688 15.9

a Antagonism of 2-Me-5-HT intracellular calcium mobilization assay. b IC50 values were determined Antagonism of 2-Me-5-HT intracellular calcium mobilization assay. b IC50 values were determined using a 0 s EC using a non-radioactive cell-based [35].were IC50 values were in determined in this triplicate. this assay, non-radioactive cell-based assay [35]. ICassay determined triplicate. In assay, In 2-Me-5HT 50 values 50 d PhPyrim value as agonist EC was nM.asc Not determined. Ph =c Phenyl; Py = Pyridine; = Pyrimidine. 50 119 value agonist was 119 dnM. Not determined. = Phenyl; Py = Pyridine; 2-Me-5HT′s Pyrim = Pyrimidine.

a

3. Discussion

3. Discussion

The vast majority of 5-HT6 R ligands are highly basic as would be expected for serotonergic The vast majority of 5-HT6R ligands are highly basic as would be expected for serotonergic ligands [36]. However, it has not been convincingly demonstrated the need for a basic side chain for ligands [36]. However, it has not been convincingly demonstrated the need for a basic side chain for effective interaction with thethe 5-HT Keeping in mind this issue, we look for new arylsulfonyl 6 receptor. effective interaction with 5-HT 6 receptor. Keeping in mind this issue, we look for new arylsulfonyl derivatives withwith a less basic character ligandsalready alreadyreported. reported. With we introduced derivatives a less basic characterthan thanthe the ligands With thisthis aim,aim, we introduced a keto or alcohol inthe the linker of new compounds. Inseries the synthesized, new series alcohol synthesized, alcohol a keto or alcoholgroup group in linker of new compounds. In the new derivatives consistently exhibited higher binding affinities when compared to parent keto compounds, except in the derivatives consistently exhibited higher binding affinities when compared to parent keto compounds, pairs of compounds 3c–4c, 3h–4h, and3h–4h, 3l–4l, where Ki values remained at about the same orderthe of same except in the pairs of compounds 3c–4c, and 3l–4l, where Ki values remained at about The influence of the carbonyl reduction receptor binding affinitybinding is remarkable ordermagnitude. of magnitude. The influence of the group carbonyl groupinreduction in receptor affinity is for compounds 4b (pKi = 7.87), 4g (pKi = 7.73) and 4j (pKi = 7.83), for which the affinity increases remarkable for compounds 4b (pKi = 7.87), 4g (pKi = 7.73) and 4j (pKi = 7.83), for which the affinity approximately 100–1000 fold. increases approximately 100–1000 fold. The change in affinity might be related to the ability of the compounds to establish an ionic The change in D106 affinity mighteither be related toathe abilitybond of the compounds to establish interaction with (Asp3.32), through hydrogen involving the alcohol group or an the ionic interaction with D106 (Asp3.32), either through a hydrogen bond involving the alcohol group protonatable nitrogen atom of the piperazine ring. For example, while the experimental pKa value ofor the protonatable nitrogen ring. For while thesee experimental pKa value of compound keto 3b atom is 5.72,ofinthe the piperazine alcohol derivative 4g itexample, is 6.69 (For details section 4.4), allowing compound 3b of is ionized 5.72, in fraction the alcohol derivative pH. 4g itThese is 6.69 details see section 4.4), a a higherketo degree at physiological pK(For a values are in agreement with allowing those calculated where the keto pKa values ~5.0 and alcohol pKa values arethose higher degree in of silico ionized fraction at average physiological pH.are These pKathe values areaverage in agreement with near toin7.0. Reduction carbonyl group provides a higher flexibility thus allowing calculated silico where of thethe keto average pKaalso values are ~5.0 and the alcohol average pKathe values compounds to be accommodated better within the binding site of the receptor. Moreover, for the are near to 7.0. Reduction of the carbonyl group also provides a higher flexibility thus allowing the hydroxylic compounds series (4a–4m), the ionized fraction present at physiological pH seems to be compounds to be accommodated better within the binding site of the receptor. Moreover, for the a critical property, as the most potent ligands (higher pKi) have a higher ionized fraction probably hydroxylic compounds series (4a–4m), the ionized fraction present at physiological pH seems to be owing to the higher pKa. a critical We property, as the most potent ligands (higherform pKiof ) have a higher ionized fraction probably performed docking experiments on the neutral the ligands, finding relevant interactions owing to the higher pK . between ligands and athe receptor active site. Both the ketone and alcohol derivatives bind with virtually Wesame performed docking thebinding neutral of6Rthe ligands, the set of residues withinexperiments the orthostericon ligand siteform of 5-HT (Figure 4A). finding relevant interactions between ligands and the receptor active site. Both the ketone and alcohol derivatives bind with virtually the same set of residues within the orthosteric ligand binding site of 5-HT6 R (Figure 4A). The neutral and ionized forms of compound 4j have similar binding modes (Figure 4B), with the naphthalene ring attached to sulfonyl group occupying the hydrophobic pocket 1 and 2-methoxyphenyl group pending over piperazine ring filling pocket 2. A more stable ion-interaction

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network accompanied by a small structural reorganization improves the H-bond and aromatic contributions to the binding energy, through 2-methoxyphenyl group H-bond interaction with N86 (3.28) as well as naphthalene aromatic interactions with F188 (5.38). However, the non-ionized form showed a higher aromatic and lipophilic contribution to the binding energy, revealing that an important part of the affinity at the receptor is given by the interaction between this neutral form of the ligands and the active site, a similar finding to that of Harris et al. [37]. Therefore, we propose that ligand biological activity resides in a combination of both protonated and neutral forms. Molecules 2016, 21, 1070

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Figure 4. (A) 2D schematic representation of the binding mode for compounds 3j and 4j, and (B)

Figure 4. FRED-predicted (A) 2D schematic representation of the binding mode for compounds 3j and 4j, and binding mode for the (S) stereoisomer of compound 4j in its ionized (left) and (B) FRED-predicted binding mode for5-HT the6R(S) stereoisomer compound 4j intoits ligand binding site,of and the contribution theionized binding (left) and non-ionized (right) forms within energy as estimated by the Ludi functions are shown. non-ionized (right) forms within 5-HT36scoring R ligand binding site, and the contribution to the binding energy as estimated by the Ludi 3 scoring functions are shown.

The neutral and ionized forms of compound 4j have similar binding modes (Figure 4B), with the naphthalene ring attached to sulfonyl group occupying the hydrophobic pocket 1 and 2-methoxyphenyl group pending overmodifications piperazine ringtofilling pocket 2. Aattached more stable ion-interaction network Following, structural the aryl group to sulfonyl group were explored, accompanied by a small structural reorganization the H-bond andbinding aromatic affinity contributions to receptor. showing that electron-withdrawing groups provedimproves detrimental to the on the the binding energy, through 2-methoxyphenyl group H-bond interaction with N86 (3.28) as well as For instance, when comparing the three 4-haloaryl groups used as substituents in the series of naphthalene aromatic interactions with F188 (5.38). However, the non-ionized form showed a higher piperazinyl compounds, it cancontribution be noted to that increases in thethat order: 4-F (3e,part pKof 4.72) < 4-Cl aromatic and lipophilic theaffinity binding energy, revealing an important i =the affinity at the receptor is given by the interaction between this neutral form of the ligands and the active (3d, pKi = 5.07) < 4-I (3h, pKi = 6.38). Similarly, compounds 3l and 4l showed better affinity than the site,(pK a similar finding to that of Harris et al. [37]. Therefore, we propose that ligand biological activity pair 3m–4m i : 4-OMe-Ph > 3,5-diF-Ph), as previously shown for indole-3-piperazinyl derivatives, resides in a combination of both protonated and neutral forms. for which electron-donating groups in the aryl sulfonamide moiety were preferred for receptor binding Following, structural modifications to the aryl group attached to sulfonyl group were explored, instead of showing halogen atoms [16]. In our study, the 4-iodo substitution represents special that electron-withdrawing groups proved detrimental to the binding affinity onathe receptor.case, For given its instance, when(comparable comparing the three groups used as substituents theof series piperazinyl low electronegativity to a 4-haloaryl carbon atom), standing out as in one theofbest substituents for can be noted thatnaphthyl affinity increases in the order:as4-F (3e, pKi group = 4.72) 3,5-diF-Ph), as previously shown for indole-3-piperazinyl derivatives, for which substituentelectron-donating at this position on 3-sulfonylindazole reportedfor byreceptor Liu etbinding al. [38]. Regarding the groups in the aryl sulfonamidederivatives moiety were preferred instead of halogen atoms [16]. In our study, the 4-iodo substitution represents a special case, given its low aryl group pending over piperazine ring the best results were obtained with the 2-methoxyphenyl electronegativity (comparable to a carbon atom), standing out as one of the best substituents for this series group, as exemplified with compounds 4b (pKi = 7.87), 4g (pKi = 7.73) and 4j (pKi = 7.83), which (4f–4h). In addition, when naphthyl was employed as the aryl group attached to the sulfonyl group, we represent the lead compounds of this series. When these values are compared with a pyridyl group, a obtained one of the best binding affinities (4j, pKi = 7.83), reinforcing the SAR for the aryl substituent at decrease inthis affinity ofonabout 10–35 timesderivatives is observed using group (4a pKthe 6.32; 4f pKi = 6.43; position 3-sulfonylindazole reported bythe Liu latter et al. [38]. Regarding group i =aryl pending over piperazine ringisthe results were obtained with we the use 2-methoxyphenyl 4i pKi = 6.83). Even more marked thebest decrease in affinity when pyrimidinylgroup, as theasaryl group

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exemplified with compounds 4b (pKi = 7.87), 4g (pKi = 7.73) and 4j (pKi = 7.83), which represent the lead compounds of this series. When these values are compared with a pyridyl group, a decrease in affinity about 10–35 times is observed using the latter group (4a pKi = 6.32; 4f pKi = 6.43; 4i pKi = 6.83). Even (4c pKof i = 6.07; 4h pKi = 6.21; 4k pKi = 6.22). It should be noted that the 2-methoxyphenyl piperazine more marked is the lower decrease in affinity when we use pyrimidinyl as the aryl group (4c pK[10,39]. i = 6.07; 4h exhibits a substantially affinity as compared with the compounds here reported pKi = 6.21; 4k pKi = 6.22). It should be noted that the 2-methoxyphenyl piperazine exhibits a substantially lower affinity as compared with the compounds here reported [10,39]. 4. Materials and Methods 4. Materials and Methods 4.1. Molecular Modeling and Validation of the 5-HT6 Receptor

Human β2 -AR crystaland structure a template to model the human 5-HT6 receptor 4.1. Molecular Modeling Validationwas of theused 5-HTas 6 Receptor (5-HT6 R). Human The selection of this structure as template basedtoon basicthe local alignment search tool β2-AR crystal structure was used as a was template model human 5-HT6 receptor (BLAST) search results and phylogenetic studies [40,41]. The human 5-HT6 Ralignment shares 31.1% (5-HT 6R). The selection of this structure as template was based on basic local searchsequence tool identity and 53.9% similarity withstudies human[40,41]. β2 -AR. The sequence wassequence analyzed to (BLAST) searchsequence results and phylogenetic The human 5-HT6alignment R shares 31.1% and 53.9% of sequence similarity with throughout human β2-AR. The sequence and alignment was analyzed to check identity the preservation conserved residues the alignment motifs. check the preservation of conserved residues throughout the alignment and motifs. Multiple sequence alignment (Figure 5) and 5-HT6 R model construction was performed using Multiple sequenceinalignment (Figure and v2.1 5-HT(Accelrys 6R model construction was performed using Modeller as implemented Discovery Studio5)(DS) Inc., San Diego, CA, USA). Figure 5 Modeller as implemented in Discovery Studio (DS) v2.1 San Diego, CA, USA). 5 shows the final alignment used to generate a set of 100(Accelrys models, Inc., of which the best modelFigure according shows the final alignment used to generate a set of 100 models, of which the best model according to to the internal scoring function of the program (PDF score) was subjected to an energy minimization the internal scoring function of the program (PDF score) was subjected to an energy minimization protocol in order to relax the structure and optimize bond geometry. protocol in order to relax the structure and optimize bond geometry.

Figure 5. Sequence alignment between 5-HT6R and β2-AR. Red bars indicate transmembrane helical

Figure 5. Sequence alignment between 5-HT6 R and β2-AR. Red bars indicate transmembrane helical regions (TMH) and the brown line connects the residues forming the disulfide bridge. The most regions (TMH) and the brown line connects the residues forming the disulfide bridge. The most conserved residues on each TMH are denoted with the Ballesteros-Weinstein nomenclature [42]. conserved residues on each TMH are denoted with the Ballesteros-Weinstein nomenclature [42].

A 5000-step steepest descent minimization followed by the conjugate gradient minimization −5 kcal/mol algorithm over 10,000 steps or until the energy decrease between steps became less than 1.0minimization A 5000-step steepest descent minimization followed by the conjugate gradient was used. The minimization protocol was carried out in a vacuum using a dielectric constant 4 in algorithm over 10,000 steps or until the energy decrease between steps became less than 1.0−5ofkcal/mol order to mimic membrane environment, with a 14 Å cut-off for non-bonded interactions, and the was used. The minimization protocol was carried out in a vacuum using a dielectric constant of 4 CHARMm force field [43]. The obtained 5-HT6R model contains residues 21–305 and a disulfide bridge in order to mimic membrane environment, with a 14 Å cut-off for non-bonded interactions, and the between residues Cys99 and Cys180. The resulting model was superimposed with the template β2-AR CHARMm force field [43]. deviation The obtained 5-HT contains residues 21–305 and a of disulfide 6 RÅmodel and a root-mean-square (RMSD) of 0.8 based on alpha carbon atoms (Cα-RMSD) 212 bridgeequivalent between residues The Ramachandran resulting modelplot wasanalysis superimposed with the template residues Cys99 (Figureand 6) Cys180. was found. with PROCHECK as β2-ARimplemented and a root-mean-square deviation (RMSD) of 0.8 Å based on alpha[44], carbon (Cα-RMSD) in NIH SAVES server (http://nihserver.mbi.ucla.edu/SAVES/) showsatoms that the model of 212has equivalent (Figure 6) in was analysis with PROCHECK more thanresidues 98% of the residues thefound. allowedRamachandran regions (94.8% in plot the most favored regions, 2.8% in as the additional allowed regions and (http://nihserver.mbi.ucla.edu/SAVES/) 1.6% in generously allowed regions). Only two residues (0.8%)that fall the implemented in NIH SAVES server [44], shows disallowed regions (Figure 6). To the reliability the 5-HT 6R model structure,regions, we modelinto hasthe more than 98% of the residues inevaluate the allowed regions of (94.8% in the most favored used the ProSA-web server which set a Z-score of −4.3 for the human 5-HT 6R model structure [45]. 2.8% in the additional allowed regions and 1.6% in generously allowed regions). Only two residues This value is consistent with the Z-score distribution of experimentally determined structures in the (0.8%) fall into the disallowed regions (Figure 6). To evaluate the reliability of the 5-HT6 R model PDB [46].

structure, we used the ProSA-web server which set a Z-score of −4.3 for the human 5-HT6 R model structure [45]. This value is consistent with the Z-score distribution of experimentally determined structures in the PDB [46].

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Figure 6. Validation of the obtained 5-HT6R model. (A) Superposition of the obtained 5-HT6R model

Figure (in 6. Validation of the obtained 5-HT6 R(in model. (A) Superposition of the obtained 5-HT6 R model blue); (B) Ramachandran plot for the final minimized red) and the β2-AR structural template (in red)5-HT and6Rthe β -AR structural template (in blue); Ramachandran for the final minimized 2 red color indicates the most favored (B) model, regions, yellow color plot for additional allowed 5-HT6 Rregions, model, red color indicates the most favored regions, yellow color for additional light yellow shows generously allowed regions and white color denotes the disallowed regions; allowed (C) ProSA-web Z-score plotgenerously for 5-HT6R model. regions, light yellow shows allowed regions and white color denotes the disallowed regions; (C) ProSA-web Z-score plot for 5-HT6 R model. 4.2. Receptor-Ligand Interaction Studies

Molecular Interaction docking of Studies the Maybridge rule of three fragment database (2500 fragments) and 4.2. Receptor-Ligand synthesized compounds was performed using FRED v3.0.1 (OpenEye Scientific Software, Santa Fe, NM,

Molecular docking of the of three database (2500 fragments) and USA) [47–49]. The binding sitesMaybridge in the 5-HT6R rule were defined andfragment prepared using the FRED receptor GUI, considering the residues involved in the interaction with the 5-HT 6 R binding site as previously defined synthesized compounds was performed using FRED v3.0.1 (OpenEye Scientific Software, Santa Fe, in the pharmacophore proposed et al.defined [22]., and those found in cavity search NM, USA) [47–49]. The model binding sites by in Lopez-Rodríguez the 5-HT6 R were and prepared using the FRED (Table 4) with Discovery Studio v2.1 (Accelrys Inc.). Pocket 1 and Pocket 2 correspond to Site 3 and 4, receptor GUI, considering the residues involved in the interaction with the 5-HT6 R binding site as respectively. Site 1 corresponds to the whole orthosteric binding pocket in 5-HT6R. previously defined in the pharmacophore model proposed by Lopez-Rodríguez et al. [22]., and those 4. Characteristics of identified binding sites(Accelrys based on cavities. found in cavity search Table (Table 4) with Discovery Studio v2.1 Inc.). Pocket 1 and Pocket 2 Y Z Volume (Å3) whole Point Count * correspond to Site 3Site and 4,Xrespectively. Site 1Threshold corresponds to the orthosteric binding pocket 1 −31.178 6.651 7.495 2.5 586.250 4690 in 5-HT6 R. 2 −35.928 35.651 7.995 2.5 248.625 1989 3 −34.678 19.151 7.995 2.5 48.750 390 Table 4. Characteristics of identified binding30.875 sites based on247 cavities. 4 −26.678 50.151 12.995 2.5 5 −20.678 10.151 12.995 2.5 29.750 238 Site6 X Threshold 23.375 Point Count * Volume (Å3 ) −29.928 24.901Y 0.245 Z 2.5 187 7 −25.928 23.651 11.745 2.5 21.875 175 1 −31.178 6.651 7.495 2.5 586.250 4690 35.651−1.2557.995 2.5 2.5 248.625 2 8 −35.928 42.901 −20.428 14.000 112 1989 3 9 −34.678 26.901 19.15110.2457.995 2.5 2.5 −44.678 13.25048.750 106 390 4 −26.678 30.651 50.151 10 −32.178 −2.75512.995 2.5 2.5 12.87530.875 103 247 5 −20.678 10.151 12.995 2.5 29.750 238 a grid size 2.5 of 2.5 Å. 6 −29.928 24.901* With0.245 23.375 187 7 −25.928 23.651 11.745 2.5 21.875 175 Structure 8canonicalization and salt removal of the Maybridge rule of 3 fragment database −20.428 42.901 −1.255 2.5 14.000 112 (downloadable9 at www.maybridge.com) was performed v15.12.14 −44.678 26.901 10.245 2.5 using Standardizer 13.250 106 (ChemAxon −32.178 −2.755 2.5 12.875 103 using Marvin Ltd., Budapest,10Hungary). For the30.651 synthesized compounds, ligands were constructed

With as a grid 2.5 Å. Sketch v15.12.14 (ChemAxon Ltd.) and *saved SDFsize file.ofMulticonformer libraries of compounds were prepared using OMEGA v2.5.1.4 (OpenEye Scientific Software) [50,51]. QUACPAC v1.6.3.1 (OpenEye Structure canonicalization salt the to Maybridge of Candidate 3 fragment Scientific Software) was used toand assign theremoval AM1BCC of charges the libraries rule [52–54]. posesdatabase (downloadable at www.maybridge.com) was were performed Standardizer (ChemAxon of the ligands within the receptor sites (100) obtainedusing and optimized using v15.12.14 the Chemgauss4 scoring function. Consensus structures of the poses returned from exhaustive docking and optimisation Ltd., Budapest, Hungary). For the synthesized compounds, ligands were constructed using Marvin obtained by consensus scoring the as PLP, Chemscore and Chemgauss3 scoring functions [55]. Sketch were v15.12.14 (ChemAxon Ltd.) andusing saved SDF file. Multiconformer libraries of compounds were Finally, the top ranked binding modes for each compound were minimized using the CHARMM22 prepared using OMEGA v2.5.1.4 (OpenEye Scientific Software) [50,51]. QUACPAC v1.6.3.1 (OpenEye force field in Discovery Studio v2.1 (Accelrys Inc.). The minimization protocol allowed the side chains Scientific Software) was6used to assign thecentroid AM1BCC the libraries [52–54]. Candidate of residue within Å from the mass of allcharges docked to ligands, using the conjugate gradient poses of the ligands within the receptor sites (100) were obtained and optimized using the Chemgauss4 algorithm until convergence criteria of 0.001 kcal/mol/Å for the RMS of the energy gradient. Table 5 scoring resumes the energy evaluation each obtained complex using the PLP,and LigScore, PMF, function. Consensus structures of performed the poses for returned from exhaustive docking optimisation were and LUDI scoring functions, and the consensus scoring available with Discovery Studio v2.1 obtained by consensus scoring using the PLP, Chemscore and Chemgauss3 scoring functions [55]. (Accelrys Inc.).

Finally, the top ranked binding modes for each compound were minimized using the CHARMM22 force field in Discovery Studio v2.1 (Accelrys Inc.). The minimization protocol allowed the side chains of residue within 6 Å from the mass centroid of all docked ligands, using the conjugate gradient algorithm until convergence criteria of 0.001 kcal/mol/Å for the RMS of the energy gradient. Table 5 resumes the energy evaluation performed for each obtained complex using the PLP, LigScore, PMF, and LUDI scoring functions, and the consensus scoring available with Discovery Studio v2.1 (Accelrys Inc.).

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Table 5. FRED docking scores (Chemgauss4) and other scoring functions for synthesized compounds. Name

Index

pKi

3j 4i_r 4j_s 3i 4j_r 4i_s 3k 4k_s 4k_r 3b 3a 4b_r 4b_s 4e_s 4a_r 4c_s 4c_r 3m 4m_s 4e_r 4g_r 4f_r 3g 4d_r 3f 4a_s 4g_s 4m_r 4d_s 3c 4h_s 4h_r 3e 4f_s 4l_s 3d 3l 4l_r 3h

10 30 33 9 32 31 11 35 34 2 1 16 17 23 14 19 18 13 39 22 26 24 7 20 6 15 27 38 21 3 29 28 5 25 37 4 12 36 8

5.9 6.83 7.83 5.91 7.83 6.83 5.85 6.22 6.22 4.97 5.75 7.87 7.87 5.66 6.32 6.07 6.07 4.65 5.12 5.66 7.73 6.43 5.72 5.43 6.1 6.32 7.73 5.12 5.43 6.11 6.21 6.21 4.72 6.43 6.05 5.07 6.35 6.05 6.38

ChemGauss4 LigScore1

−19.57 −19.36 −19.2 −19.06 −18.74 −18.69 −18.58 −18.22 −17.71 −16.92 −16.73 −16.52 −16.52 −16.02 −15.83 −15.62 −15.21 −15.17 −15.14 −15.02 −14.89 −14.83 −14.68 −14.61 −14.5 −14.42 −14.33 −14.22 −14.07 −14.04 −13.9 −13.87 −13.86 −13.77 −13.65 −13.55 −13.45 −13.03 −12.46

3.5 4.71 4.15 3.25 4.24 1.13 3.78 3.04 2.45 −3.23 −0.78 −10.8 −10.8 2.2 4.04 1.94 1.4 3.43 3.79 2.74 −20.63 −3.18 −7.37 3.32 1.12 −1.95 0.51 −0.29 2.62 2.45 −20.04 1.06 1.65 −3.61 2.96 3.07 3.55 −2.86 −1.04

LigScore2

PLP1

PLP2

Jain

PMF

PMF04

Ludi_1

Ludi_2

Ludi_3

∆G Ludi_1

∆G Ludi_2

∆G Ludi_3

Consensus

4.72 6.25 5.34 4 5.38 0.91 5.17 4.05 2.6 −6.13 −1.85 −17.97 −17.97 2.38 5.39 2.08 1.03 4.5 4.93 3.57 −34.04 −6.58 −10.74 3.88 2.88 −3.57 1.64 −1.12 2.71 3.16 −33.18 0.61 1.18 −5.79 4.15 3.55 4.73 −5.51 −1.54

139.88 136.12 140.77 125.45 137.88 131.81 127.85 126.09 128.65 98.92 106.66 85.74 85.74 119.97 110.42 117.91 115.91 104.81 99.87 111.75 107.72 108.34 78.7 107.75 93.3 103.05 97.13 93.7 103.82 98.42 102.75 105.96 97.36 92.37 101.24 105.47 93.97 92.12 92.3

140.26 132.47 142.09 122.41 139.38 131.06 124.86 123.73 124.28 108.88 109.34 100.29 100.29 115.27 110.89 116.9 111.3 101.28 103.34 103.89 112.42 112.04 75.52 105.26 91.41 104.18 95 91.7 102.47 96.69 112.55 101.81 103.7 90.26 99.41 98.38 90.15 92.12 88.74

6.05 5.99 5.92 6.49 6.94 5.65 5 5.62 5.59 7.62 4.59 5.15 5.15 5.14 5.5 4.88 5.13 4.67 4.52 4.76 5.82 5.56 5.54 5.85 4.69 4.43 5.79 4.12 4.15 4.61 5.45 4.83 5.89 4.54 4.39 4.03 4.49 4.03 5.12

579.9 558.69 613.33 575.64 609.55 549.81 536.9 547.04 574.21 549.29 520.04 542.51 542.51 486.2 564.73 501.32 538.29 353.06 420.98 505.89 513.78 517.06 450.15 511.12 425.98 525.34 507.06 421.32 495.37 530.61 463.4 518.85 467.09 459.24 475.3 487.82 494.34 466.35 433.2

546.47 533.96 583.74 532.3 586.04 530.82 515.62 530.75 554.39 521.19 492.33 531.71 531.71 494.54 546.06 507.06 530.29 373.45 438.57 512.95 514.57 509.01 434.06 504.56 412.79 513.3 491.66 437.9 480.52 510.38 471.58 512.81 474 453.03 478.99 466.13 467.72 460.71 419.93

810 705 826 748 806 683 756 633 724 778 812 781 781 546 654 585 633 533 501 597 719 689 637 645 590 615 654 435 606 726 642 633 687 584 509 717 590 509 631

687 615 717 632 672 605 643 569 625 657 644 678 678 528 564 526 562 494 497 539 659 598 589 560 520 573 575 444 510 612 590 554 597 534 481 593 498 481 555

1078 1006 1118 921 955 1006 1107 875 976 1062 1099 1247 1247 878 839 880 805 697 756 770 1054 887 937 856 852 847 905 648 745 886 942 847 1056 811 681 751 679 695 891

−11.05 −9.61 −11.26 −10.2 −10.99 −9.31 −10.31 −8.63 −9.87 −10.61 −11.07 −10.65 −10.65 −7.45 −8.92 −7.98 −8.63 −7.27 −6.83 −8.14 −9.8 −9.4 −8.69 −8.8 −8.05 −8.39 −8.92 −5.93 −8.26 −9.9 −8.75 −8.63 −9.37 −7.96 −6.94 −9.78 −8.05 −6.94 −8.6

−9.37 −8.39 −9.78 −8.62 −9.16 −8.25 −8.77 −7.76 −8.52 −8.96 −8.78 −9.25 −9.25 −7.2 −7.69 −7.17 −7.66 −6.74 −6.78 −7.35 −8.99 −8.15 −8.03 −7.64 −7.09 −7.81 −7.84 −6.05 −6.95 −8.35 −8.05 −7.55 −8.14 −7.28 −6.56 −8.09 −6.79 −6.56 −7.57

−14.7 −13.72 −15.25 −12.56 −13.02 −13.72 −15.1 −11.93 −13.31 −14.48 −14.99 −17.01 −17.01 −11.97 −11.44 −12 −10.98 −9.5 −10.31 −10.5 −14.37 −12.1 −12.78 −11.67 −11.62 −11.55 −12.34 −8.84 −10.16 −12.08 −12.85 −11.55 −14.4 −11.06 −9.29 −10.24 −9.26 −9.48 −12.15

11 11 11 11 11 11 11 11 11 9 11 8 8 10 11 10 11 6 5 11 9 9 5 11 6 8 10 3 8 11 8 10 10 3 6 8 6 1 6

∆G binding from Ludi Scores calculated as ∆G = LudiScore/−73.33, in kcal/mol.

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Molecules 2016, 21, 1070 Molecules 2016, 21, 1070

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4.3. 4.3. Syntheses Syntheses and and Characterization Characterization Procedures Procedures 4.3. Syntheses and Characterization Procedures All All organic organic solvents solvents used used for for the the synthesis synthesis were were of of analytical analytical grade. grade. All All reagents reagents used used were were purchased from Sigma-Aldrich (St. Louis, MO, USA), Merck (Kenilworth, NJ, USA) or AK Scientific All organic solvents used (St. for the synthesis wereMerck of analytical grade.NJ, AllUSA) reagents used were purchased from Sigma-Aldrich Louis, MO, USA), (Kenilworth, or AK Scientific (Union CA, used as Melting points were on Stuart Scientific purchased from Sigma-Aldrich Louis, MO, USA), Merck (Kenilworth, NJ, USA) AK Scientific (Union City, City, CA,USA) USA)and andwere were(St. used asreceived. received. Melting points were determined determined on aaor Stuart Scientific SMP30 apparatus (Bibby Scientific Limited, Staffordshire, United Kingdom) and are uncorrected. NMR (Union CA, USA) and Scientific were usedLimited, as received. Melting points wereKingdom) determinedand on aare Stuart Scientific SMP30 City, apparatus (Bibby Staffordshire, United uncorrected. 1 H and spectra were recorded on a Bruker Avance III HD 400 (Billerica, MA, USA) at 400 MHz for SMP30 apparatus Scientific Limited, Staffordshire, United Kingdom) and are uncorrected. NMR spectra were(Bibby recorded on a Bruker Avance III HD 400 (Billerica, MA, USA) at 400 MHz for 13 C-NMR spectra were recorded in CDCl unless otherwise indicated, using the solvent 100 MHz for 3 1H and 13 NMR spectra were recorded on a Bruker Avance III HD 400 (Billerica, MA, USA) at 400 MHz for 100 MHz for C-NMR spectra were recorded in CDCl3 unless otherwise indicated, using the 1signal 13 as reference. The chemical shifts are expressed in ppm (δ scale) downfield from tetramethylsilane H and 100 MHz C-NMRThe spectra were recorded CDCl3 unless otherwise indicated, usingfrom the solvent signal asfor reference. chemical shifts areinexpressed in ppm (δ scale) downfield (TMS), and coupling constants values (J) are given in Hertz. The IR spectra were obtained on a Bruker solvent signal as reference. The chemical shifts are expressed in ppm (δ scale) downfield from tetramethylsilane (TMS), and coupling constants values (J) are given in Hertz. The IR spectra were Vector 22 on spectrophotometer MA, USA) using KBr Column chromatography was tetramethylsilane (TMS), and (Billerica, coupling constants values (J) arediscs. givenUSA) in Hertz. The spectra were obtained a Bruker Vector 22 spectrophotometer (Billerica, MA, using KBrIRdiscs. Column performed on Merck silica gel 60 (70–230 mesh). Thin layer chromatographic separations were obtained on a Bruker Vector 22 spectrophotometer USA) using KBr discs. Column chromatography was performed on Merck silica gel (Billerica, 60 (70–230MA, mesh). Thin layer chromatographic performed on Merck silica gel 60 (70–230 mesh) chromatofoils. Elemental analyses were on chromatography was performed on Merck silica gel 60 (70–230 mesh). Thin layer chromatographic separations were performed on Merck silica gel 60 (70–230 mesh) chromatofoils. Elemental performed analyses were a FISONS EA 1108 CHNS-O analyzer. separations were performed Merck silicaanalyzer. gel 60 (70–230 mesh) chromatofoils. Elemental analyses were performed on a FISONS EA on 1108 CHNS-O

performed on a FISONS EA 1108 CHNS-O analyzer. 2-Bromo-1-(1H-indol-3-yl)ethanone 2-Bromo-1-(1H-indol-3-yl)ethanone (1) (1) 2-Bromo-1-(1H-indol-3-yl)ethanone (1) H4' H5'

H4'

O O

H5'

H2 H2 H2 HH22'

H6' H6'

Br Br

7'

H

N H N H

H2'

H7'

To aasolution solutionofof indole (18.53 g, 8.53 mmol) dry CH2Cl2 (30 mL) was added anhydrous zinc To indole (1 g, mmol) in dryinCH 2 Cl2 (30 mL) was added anhydrous zinc chloride To a solution of indole (1 g, 8.53 mmol) in dry CH 2Cl2 (30 mL) was added anhydrous zinc chloride (1.7 g, 12.45 mmol) under N 2 atmosphere. Immediately methylmagnesium bromide (6.1 mL, (1.7 g, 12.45 mmol) under N2 atmosphere. Immediately methylmagnesium bromide (6.1 mL, 8.53 mmol, chloride (1.7 g, 12.45 mmol) under N 2 atmosphere. Immediately methylmagnesium bromide (6.1 mL, 8.53Mmmol, 1.4 M in THF/toluene 1:3) was slowly 20 min and the was 1.4 in THF/toluene 1:3) was slowly added overadded 20 minover period and period the mixture wasmixture vigorously 8.53 mmol, M room infor THF/toluene 1:3) was slowly added overtime, 20 min period (0.84 and the was vigorously stirred 2temperature. h at room temperature. After this bromoacetyl chloride (0.84 mL, stirred for 21.4 h at After this time, bromoacetyl chloride mL,mixture 9.65 mmol) vigorously stirred for 2 h at room temperature. After this time, bromoacetyl chloride (0.84 mL, 9.65 mmol) was added in one portion and mixture was stirred until that the starting material had was added in one portion and mixture was stirred until that the starting material had disappeared 9.65 mmol) was added in one portion and mixture was stirred until that the starting material had disappeared by checking TLC. The stopped adding by dilution adding an aqueoussolution saturated by checking TLC. The reaction wasreaction stoppedwas by dilution an aqueous saturated of disappeared by checking TLC. The reaction was stopped by dilution adding an aqueous saturated solution of ammonium chloride (50 mL) and extracted with CH 2 Cl 2 (3 × 30 mL). The combined organic ammonium chloride (50 mL) and extracted with CH2 Cl2 (3 × 30 mL). The combined organic layers solution of ammonium chloride (50sodium mL) and extracted with CHthe 2of Clthe 2 (3 × 30 mL). The combined organica layersdried were driedanhydrous with anhydrous sulfate removal solvent under vacuum afforded were with sodium sulfate and and removal of solvent under vacuum afforded layers were dried with anhydrous sodium sulfate and removal of the solvent under vacuum afforded a residue, whichwas wasfurther furtherpurified purifiedby bycolumn columnchromatography chromatographyon onsilica silicagel gel(CH (CH22Cl Cl22/AcOEt / AcOEt 9:1) residue, which 9:1) ato which was further purified by column chromatography on silica gel (CH 2Cl2/◦ AcOEt 9:1) toresidue, give 1260 mg of (1) as a dark red amorphous powder. Yield: 62% m.p.: 160.3–161.0 °C; IR (KBr) give 1260 mg of (1) as a dark red amorphous powder. Yield: 62% m.p.: 160.3–161.0 C; IR (KBr) −11 to 12601638, mg of (1) 750. as a 1dark red (acetone-d amorphous 62% m.p.: 160.3–161.0 (KBr) − 1H-NMR cmgive : :3210, 1431, δδ(ppm): 11.21 1H, N-H), 8.42 3.2 Hz, 1H, cm 3210, 1638, 1431, 750. H-NMR (acetone-d6)6 )powder. (ppm):Yield: 11.21(s, (s, 1H, N-H), 8.42 (d, (d, JJ ==°C; 3.2IR Hz, 1H, −1: 3210, 1638, 1431, 750. 1H-NMR (acetone-d6) δ (ppm): 11.21 (s, 1H, N-H), 8.42 (d, J = 3.2 Hz, 1H, cm 0 ), 8.31 0 , H-6 0 ), 4.56 H-2′), 8.31 (dd, (dd, JJ = = 7.8 (m, 2H, 2H, H-5 H-5′, H-6′), 4.56 H-2 7.8 and and 4.9 4.9 Hz, Hz, 1H, 1H, H-4′), H-40 ),7.59–7.53 7.59–7.53 (m, (m, 1H, 1H, H-7′), H-70 ), 7.31–7.24 7.31–7.24 (m, 13C-NMR H-2′), (dd, J = 7.8 and 4.9 Hz, 1H, H-4′), 7.59–7.53 (m, 1H, H-7′), 7.31–7.24 (m, 2H, H-5′, H-6′),113.4, 4.56 13 (s, 2H, 2H,8.31 H-2). (acetone-d 6)) δ (ppm): 187.5, 138.3, 135.3, 127.3, 124.7, 123.5, 123.1, 115.6, (s, H-2). C-NMR (acetone-d 6 δ (ppm): 187.5, 138.3, 135.3, 127.3, 124.7, 123.5, 123.1, 115.6, 113.4, 13C-NMR (acetone-d6) δ (ppm): 187.5, 138.3, 135.3, 127.3, 124.7, 123.5, 123.1, 115.6, 113.4, (s, 2H, H-2). (238.08 g/mol) calcd.: C: 50.45; H: 3.39; N: 5.88. Found: C: and 33.6. 33.6. Elemental and Elemental analysis analysis for for C C1010HH8BrNO 8 BrNO (238.08 g/mol) calcd.: C: 50.45; H: 3.39; N: 5.88. Found: 10H8BrNO (238.08 g/mol) calcd.: C: 50.45; H: 3.39; N: 5.88. Found: C: and 33.6. Elemental analysis for C 50.17; H: 3.73; N: 6.23. C: 50.17; H: 3.73; N: 6.23. 50.17; H: 3.73; N: 6.23. 4.3.1. General Procedure for 2-bromo-1-(arylsulfonyl-1H-3-yl)ethanone 2-bromo-1-(arylsulfonyl-1H-3-yl)ethanone derivatives derivatives (2a–g) (2a–g) 4.3.1. General Procedure for 2-bromo-1-(arylsulfonyl-1H-3-yl)ethanone derivatives (2a–g) 2-Bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) 2-Bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) 2-Bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a)

In a round bottom flask under N2, 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 mg, 2.1 mmol), In a round bottom flask(439 under , 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 2.1 mmol), p-toluenesulfonyl chloride mg,N22.3 mmol), DMAP (26 mg, 0.21 mmol), andmg, triethylamine p-toluenesulfonyl (439 mg,in2.3 DMAP (26 mg, the 0.21solution mmol),was andstirred triethylamine 2, and at room (0.3 mL, 2.1 mmol)chloride were dissolved 20 mmol), mL of dry CH2Cl (0.3 mL, 2.1 mmol) were dissolved in 20 mL of dry CH2Cl2, and the solution was stirred at room

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In a round bottom flask under N2 , 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 mg, 2.1 mmol), Molecules 2016, 21, 1070 13 of 33 p-toluenesulfonyl mL, Molecules 2016, 21, 1070chloride (439 mg, 2.3 mmol), DMAP (26 mg, 0.21 mmol), and triethylamine (0.3 13 of 33 2.1 mmol) were dissolved in 20 mL of dry CH2 Cl2 , and the solution was stirred at room temperature temperature until that the starting material had disappeared by checking TLC. The reaction mixture temperature thatmaterial the starting material hadby disappeared by checking TLC.mixture The reaction mixture until that the until starting had disappeared checking TLC. The reaction was quenched was quenched by dilution with CH2Cl2 (30 mL), and the organic extract was washed with 1N HCl wasdilution quenched byCH dilution with CH 2 Cl 2 (30 mL), and the organic extract was washed with 1N HCl by with Cl (30 mL), and the organic extract was washed with 1 N HCl (20 mL). The 2 was dried over anhydrous Na2SO4, filtered and the solvent was removed (20 mL). The organic 2layer (20 mL).layer The organic layer dried over Naand 2SOthe 4, filtered solventunder was removed organic was dried overwas anhydrous Na2anhydrous SO4 , filtered solventand wasthe removed vacuum. under vacuum. The product was purified by silica gel column chromatography using CH2Cl2 to give under vacuum. The product was purified by silica gel column chromatography using CH 2 Cl 2 to give The product was purified by silica gel column chromatography using CH Cl to give 379 mg of (2a) as 2 2IR (KBr) cm−1: 1670, 379 mg of (2a) as brown crystalline plates. Yield: 46% ◦m.p.: 149.5–150.2 °C; 1536, −1: 1670, 1536, − 1 379 mg of (2a) as brown crystalline plates. Yield: 46% m.p.: 149.5–150.2 °C; IR (KBr) cm brown crystalline plates. Yield:146% m.p.: 149.5–150.2 C; IR (KBr) cm : 1670, 1536, 1392, 1175, 1137, 8.34 (s, 1H, H-2′), 8.29 (d, J 0= 7.1 Hz, 1H, H-4′), 7.93 1392, 1175, 1137, 993, 749, 569. 1H-NMR δ (ppm): 1 δ (ppm): H-2′), H-4′), 1392,749, 1175, 1137, 993, 749, 569. H-NMR 993, δ (ppm): (s, 1H, H-20 ), 8.34 8.29 (s, (d,1H, J = 7.1 Hz,8.29 1H, (d, H-4J =), 7.1 7.93Hz, (d, 1H, J = 7.7 Hz,7.93 1H, (d, J0 = 7.7569. Hz, H-NMR 1H, H-7′), 7.83 (d,8.34 J = 8.4 Hz, 2H, H-2′′, H-6′′), 7.42–7.32 (m, 2H, H-5′, H-6′), 7.27 (d, 0 , H-60 ), 7.27 00 , (d, J ),= 7.83 7.7 Hz, 7.83H-2 (d,00J, =H-6 8.400 ),Hz, 2H, H-2′′, 7.42–7.32 (m, 2H, H-5′, H-6′), 7.27 (d, H-7 (d, J1H, = 8.4H-7′), Hz, 2H, 7.42–7.32 (m, H-6′′), 2H, H-5 (d, J = 8.4 Hz, 2H, H-3 13 J = 8.4 Hz, 2H, H-3′′, H-5′′), 4.59 (s, 2H, H-2), 2.37 (s, 3H, CH 3). C-NMR δ (ppm): 187.3, 146.6, 135.1, 00 Hz, 13 C-NMR J = 8.4 H-3′′, H-5′′), 4.59 (s, CH 2H,3 ).H-2), 2.37 (s,δ 3H, CH187.3, 3). 13C-NMR δ (ppm): 187.3, 146.6, H-5 4.59 2H, (s, 2H, (s, 3H, (ppm): 146.6, 135.1, 130.8135.1, (2C), 134.6,), 132.8, 130.8H-2), (2C),2.37 127.9, 127.6 (2C), 126.5, 125.6, 123.2, 118.5, 113.6, 46.5134.6, and 132.8, 22.1. Elemental 134.6, 127.6 132.8,(2C), 130.8126.5, (2C),125.6, 127.9,123.2, 127.6118.5, (2C), 113.6, 126.5,46.5 125.6, 123.2, 118.5, 113.6, 46.5 and 22.1. Elemental 127.9, and 22.1. Elemental analysis for C H BrNO 17 C:1451.75; H: 3S analysis for C17H14BrNO3S (392.27 g/mol) calcd.: C: 52.05; H: 3.60; N: 3.57; S: 8.17. Found: analysisg/mol) for C17H 14BrNO 3S (392.27 g/mol) calcd.: C:8.17. 52.05; H: 3.60; N: 3.57; S:3.97; 8.17.N:Found: C:8.43. 51.75; H: (392.27 calcd.: C: 52.05; H: 3.60; N: 3.57; S: Found: C: 51.75; H: 3.93; S: 3.97; N: 3.93; S: 8.43. 3.97; N: 3.93; S: 8.43. 2-Bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone 2-Bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone (2b) (2b) 2-Bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone (2b)

Prepared from from 2-bromo-1-(1H-indol-3-yl)ethanone 2-bromo-1-(1H-indol-3-yl)ethanone (1) (1) (500 (500 mg, mg, 2.1 2.1 mmol), mmol), p-chlorobenzenesulfonyl p-chlorobenzenesulfonyl Prepared Prepared from 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 mg, 2.1 mmol), p-chlorobenzenesulfonyl chloride (486 (486 mg, mg, 2.3 2.3 mmol), mmol),DMAP DMAP(26 (26mg, mg,0.21 0.21mmol) mmol)and andtriethylamine triethylamine(0.3 (0.3mL, mL,2.1 2.1mmol) mmol) give chloride toto give a chloride (486 mg, 2.3 mmol), DMAP (26 mg, 0.21 mmol) and triethylamine (0.3 mL, 2.1 mmol) to give a crude, which was purified by column chromatography on silica gel using CH 2 Cl 2 to afford 520 mg of crude, which was purified by column chromatography on silica gel using CH2 Cl2 to afford 520 mg of a crude, which was purified by column chromatography on silica◦gel using CH 2Cl2 to afford 520 mg of −1 : 1673, (2b) as m.p.: 158.1–159.6 °C; IR cm−1 : 1673, 1537, 1537, 1387, 1168, (2b) as brown brown crystalline crystallineplates. plates.Yield: Yield:60% 60% m.p.: 158.1–159.6 C; (KBr) IR (KBr) 1387, −1cm (2b) as brown crystalline plates. Yield: 60% m.p.: 158.1–159.6 °C; IR (KBr) cm : 1673, 1537, 1387,0 1168, 1 1 0 H-NMR δ (ppm): 8.24 (d, J = 6.0 Hz, 1H, H-4′), 8.23 (s, 1H, H-2′), 7.85 1139, 1083, 998, 756, 569. 1168, 1139, 1083, 998, 756,1569. H-NMR δ (ppm): 8.24 (d, J = 6.0 Hz, 1H, H-4 ), 8.23 (s, 1H, H-2 ), (dd, 7.85 δ (ppm): 8.24 (d, J = 6.0 Hz, 1H, H-4′), 8.23 (s, 1H, H-2′), 7.8500 (dd, 1139, 1083, 998, 756, 569. H-NMR 0 ), 7.82 00 and 00 ), 7.41 J = 7.0, 7.82 (d, J(d, = 8.8 2H, 2H, H-2′′ and H-6′′), (d, J(d, = 8.8 2H,2H, H-3′′ andand H(dd, J =1.7 7.0,Hz, 1.7 1H, Hz, H-7′), 1H, H-7 J = Hz, 8.8 Hz, H-2 H-67.41 J = Hz, 8.8 Hz, H-3 J = 7.0, 1.7 Hz, 1H, H-7′), 7.820 (d, J = 8.8 Hz, 2H, H-2′′ and H-6′′), 7.41 (d, J = 8.8 Hz, 2H, H-3′′ and H13 00 0 13 5′′), 7.37–7.29 (m,(m, 2H, H-5′ H-6′), 4.50 H-5 ), 7.37–7.29 2H, H-5and and H-6 ), 4.50(s,(s,2H, 2H,H-2). H-2). C-NMR C-NMRδ δ(ppm): (ppm):187.3, 187.3,142.2, 142.2,136.0, 136.0, 135.0, 135.0, 5′′), 7.37–7.29 (m, 2H, H-5′ and H-6′), 4.50 (s, 2H, H-2). 13C-NMR δ (ppm): 187.3, 142.2, 136.0, 135.0, 132.5, 130.5 (2C), 129.0 (2C), 127.9, 126.8, 125.9, 123.6, 119.0, 113.4 and 46.4. Elemental analysis 132.5, 130.5 (2C), 129.0 (2C), 127.9, 126.8, 125.9, 123.6, 119.0, 113.4 and 46.4. Elemental analysis for for 132.5, 130.5 (2C), 129.0 (2C), 127.9, 126.8, 125.9, 123.6, 119.0, 113.4 and 46.4. Elemental analysis for C16 H calcd.: C: C: 46.57; H:H: 2.69; N: N: 3.39; S: 7.77. Found: C: 46.42; H: 3.02; N: C H1111BrClNO BrClNO3S3 S(412.69 (412.69g/mol) g/mol) calcd.: 46.57; 2.69; 3.39; S: 7.77. Found: C: 46.42; H: 3.02; 16 C16H11BrClNO3S (412.69 g/mol) calcd.: C: 46.57; H: 2.69; N: 3.39; S: 7.77. Found: C: 46.42; H: 3.02; N: 3.54; S: 8.01. N: 3.54; S: 8.01. 3.54; S: 8.01. 2-Bromo-1-(1-(4-fluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2c) (2c) 2-Bromo-1-(1-(4-fluorophenylsulfonyl)-1H-indol-3-yl)ethanone 2-Bromo-1-(1-(4-fluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2c) H5' H5' H6' H6'

H4' H4'

O O

H7' O H7' O H2'' H2'' H3'' H3''

N N S S

Br Br

H2 H2 H2 2 H 2' H H2' O O

H6'' H6'' H5'' H5''

F F

Prepared from 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 mg, 2.1 mmol), p-fluorobenzenesulfonyl Prepared from 2-bromo-1-(1H-indol-3-yl)ethanone (1) (500 mg, 2.1 mmol), p-fluorobenzenesulfonyl p-fluorobenzenesulfonyl chloride (448 mg, 2.3 mmol), DMAP (26 mg, 0.21 mmol) and triethylamine (0.3 mL, 2.1 mmol) to give (448 mg, mg, 2.3 2.3 mmol), mmol),DMAP DMAP(26 (26mg, mg,0.21 0.21mmol) mmol)and andtriethylamine triethylamine(0.3 (0.3mL, mL,2.1 2.1mmol) mmol)totogive givea chloride (448 a crude, which was purified by column chromatography on silica gel using CH2Cl2 to give 333 mg of a crude,which whichwas waspurified purifiedbybycolumn columnchromatography chromatographyon onsilica silicagel gelusing usingCH CH 2 Cl 2 to crude, Cl to give 333 mg of 2 1538, 1381, 1167, (2c) as brown crystalline plates. Yield: 40% m.p.: 137.3–138.6◦°C; IR (KBr) cm−−1 : 21676, −1 1 brown crystalline crystalline plates. plates. Yield: Yield: 40% 40%m.p.: m.p.: 137.3–138.6 137.3–138.6 °C; IR(KBr) (KBr)cm cm :: 1676, (2c) as brown C; IR 1676,1538, 1538, 1381, 1381, 1167, 1167, 7.92 (dd, J = 9.0 and 4.8 Hz, 1184, 1137, 995, 753, 570. 11H-NMR δ (ppm): 8.24 (m, 2H, H-2′0 and H-4′), 570. H-NMR 1184, 1137, 995, 753, 570. H-NMR δ (ppm): 8.24 8.24 (m, 2H, H-2′ H-2 and and H-4′), H-40 ), 7.92 7.92 (dd, (dd, J == 9.0 9.0 and and 4.8 4.8 Hz, Hz, 2H, H-2′′ and H-6′′), 7.85 (dd, J = 7.0 and 1.6 Hz, 1H, H-7′), 7.37–7.29 (m, 2H, H-5′ and H-6′), 7.12 (t, 2H, H-2′′ and H-6′′), 7.85 (dd, J = 7.0 and 1.6 Hz, 131H, H-7′), 7.37–7.29 (m, 2H, H-5′ and H-6′), 7.12 (t, J = 8.3 Hz, 2H, H-3′′ and H-5′′), 4.50 (s, 2H, H-2). 13C-NMR δ (ppm): 187.3, 166.6 (d, J = 259.2 Hz, 1C), J = 8.3 Hz, 2H, H-3′′ and H-5′′), 4.50 (s, 2H, H-2). C-NMR δ (ppm): 187.3, 166.6 (d, J = 259.2 Hz, 1C), 135.0, 133.7 (d, J= 2.7 Hz, 1C), 132.5, 130.6 (d, J= 9.9 Hz, 2C), 127.9, 126.8, 125.8, 123.6, 118.9, 117.7 (d, 135.0, 133.7 (d, J= 2.7 Hz, 1C), 132.5, 130.6 (d, J= 9.9 Hz, 2C), 127.9, 126.8, 125.8, 123.6, 118.9, 117.7 (d, J= 23.0 Hz, 2C), 113.4 and 46.4. Elemental analysis for C16H11BrFNO3S (396.23 g/mol) calcd.: C: 48.50; J= 23.0 Hz, 2C), 113.4 and 46.4. Elemental analysis for C16H11BrFNO3S (396.23 g/mol) calcd.: C: 48.50; H: 2.80; N: 3.53; S: 8.09. Found: C: 48.23; H: 3.15; N: 3.90; S: 7.79. H: 2.80; N: 3.53; S: 8.09. Found: C: 48.23; H: 3.15; N: 3.90; S: 7.79.

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2H, H-200 and H-600 ), 7.85 (dd, J = 7.0 and 1.6 Hz, 1H, H-70 ), 7.37–7.29 (m, 2H, H-50 and H-60 ), 7.12 (t, J = 8.3 Hz, 2H, H-300 and H-500 ), 4.50 (s, 2H, H-2). 13 C-NMR δ (ppm): 187.3, 166.6 (d, J = 259.2 Hz, 1C), 135.0, 133.7 (d, J= 2.7 Hz, 1C), 132.5, 130.6 (d, J= 9.9 Hz, 2C), 127.9, 126.8, 125.8, 123.6, 118.9, 117.7 (d, J= 23.0 Hz, 2C), 113.4 and 46.4. Elemental analysis for C16 H11 BrFNO3 S (396.23 g/mol) calcd.: C: Molecules 2016, 21, 1070 14ofof33 33 48.50; H:2016, 2.80; N: 3.53; S: 8.09. Found: C: 48.23; H: 3.15; N: 3.90; S: 7.79. Molecules 21, 1070 14 2-Bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone 2-Bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone(2d) (2d) 2-Bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) 4'4' HH

Br Br

OO

22 HH 22 HH

5'5' HH

2'2' HH

NN

6'6' H

H

OO 7'7' O SS 6''6'' HH O HH 2''2'' HH 5''5'' HH 3''3'' HH

II

Preparedfrom from2-bromo-1-(1H-indol-3-yl)ethanone 2-bromo-1-(1H-indol-3-yl)ethanone(1) (1)(1(1g,g,4.22 4.22mmol), mmol),p-iodobenzenesulfonyl p-iodobenzenesulfonyl 2-bromo-1-(1H-indol-3-yl)ethanone mmol), p-iodobenzenesulfonyl Prepared chloride(1400 (1400mg, mg,4.64 4.64 mmol), DMAP (52 mg, 0.42 mmol) and triethylamine (0.6mL, mL,mmol) 4.2mmol) mmol) to (1400 mg, 4.64 mmol), DMAP (52 mg, 0.42 mmol) triethylamine 4.2 to chloride mmol), DMAP (52 mg, 0.42 mmol) andand triethylamine (0.6 (0.6 mL, 4.2 to give give crude, which waspurified purified bycolumn column chromatography on silica gel using CH 2Cl 2to to afford aacrude, was by chromatography CH 2 Cl 2 afford agive crude, whichwhich was purified by column chromatography on silicaon gelsilica usinggel CHusing Cl to afford 1142 mg 2 2 ◦ C;183–184 − 1142 mg of(2d) (2d)as asbrown browncrystalline crystalline plates. Yield:183–184 54%m.p.: m.p.: 183–184 °C; IR1 :(KBr) (KBr) cm−1−1: :1673, 1673,1537, 1537, 1142 mg plates. 54% of (2d) asof brown crystalline plates. Yield: 54%Yield: m.p.: IR (KBr)°C; cmIR 1673,cm 1537, 1388, 1167, 1 1 0 0 0 ), 1 H-NMR (ppm): 8.22 (m, 2H, H-2′ andH-4′), H-4′), 7.82Hz, (d,J1H, J==7.4 7.4 Hz, 1388,996, 1167, 1139, 996, 749, 603,569. 569. H-NMR δδ(ppm): 8.22 2H, H-2′ (d, Hz, 1388, 1167, 1139, 996, 749, 603, 1139, 749, 603, 569. H-NMR δ (ppm): 8.22 (m, 2H, H-2(m, and H-4 ), and 7.82 (d, J =7.82 7.4 H-7 00 and 00 ), 0 and 1H,H-7′), H-7′), 7.75Hz, (d,J2H, J==8.6 8.6 Hz, 2H,H-5 H-3′′ and H-5′′), 7.55 (d,JJ2H, 8.6 Hz,2H, 2H,H-2” H-2”and and H-6”), 7.31 (m, 2H, 1H, (d, Hz, 2H, H-3′′ and ==8.6 Hz, H-6”), 7.31 (m, 2H, 7.75 (d, J =7.75 8.6 H-3 7.55H-5′′), (d, J =7.55 8.6 (d, Hz, H-2” and H-6”), 7.31 (m, 2H, H-5 13 0 13 13 H-5′),and and H-6′), 4.50 (s,2H, 2H, H-2).δ (ppm): C-NMR (ppm): 187.3, 139.6, 139.3,135.0 137.2 (2C), 135.0 (2C),133.5, 133.5, H-5′ (s, H-2). C-NMR δδ(ppm): 137.2 (2C), 135.0 (2C), H-6 4.50H-6′), (s, 2H,4.50 H-2). C-NMR 187.3, 139.6,187.3, 139.3,139.6, 137.2 139.3, (2C), (2C), 133.5, 133.23, 128.6, 133.23, 128.6, 127.9, 124.2, 119.0, 103.6, 100.0 and and 46.5.for Elemental analysis for C 16 H 11 BrINO 3S 133.23, 128.6, 127.9, 124.2, 103.6, 100.0 46.5. Elemental analysis for C 16 H 11 BrINO 3S 127.9, 124.2, 119.0, 103.6, 100.0119.0, and 46.5. Elemental analysis C16 H11 BrINO S (504.14 g/mol) calcd.: 3 (504.14 g/mol) calcd.: C: 38.12; H: 2.20; N: 2.78; S: 6.36. Found: C: 37.78; H: 2.30; N: 3.07; S: 6.59. (504.14 calcd.: C: 38.12; H:Found: 2.20; N:C:2.78; S: 6.36. Found: C: 37.78; H: 2.30; N: 3.07; S: 6.59. C: 38.12;g/mol) H: 2.20; N: 2.78; S: 6.36. 37.78; H: 2.30; N: 3.07; S: 6.59. 2-Bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone(2e) (2e) 2-Bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) 2-Bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone 5'5' HH

4'4' HH

OO

Br Br 22 HH

6'6' HH

22 HH

2'2' HH NN 7' 7' H H 8''8'' OO SS OO HH 2''2'' HH

7''7'' HH

3''3'' HH

6''6'' HH 5''5'' HH

4''4'' HH

Preparedfrom from2-bromo-1-(1H-indol-3-yl)ethanone 2-bromo-1-(1H-indol-3-yl)ethanone(1) (1)(320 (320mg, mg,1.35 1.35mmol), mmol),naphthalenesulfonyl naphthalenesulfonyl 2-bromo-1-(1H-indol-3-yl)ethanone (1) Prepared chloride(310 (310mg, mg,1.35 1.35mmol), mmol),DMAP DMAP(17 (17mg, mg,0.14 0.14mmol) mmol)and andtriethylamine triethylamine(0.2 (0.2mL, mL,1.35 1.35mmol) mmol)to to chloride give a crude, which was purified by column chromatography on silica gel using CH 2 Cl 2 to afford purified by by column column chromatography chromatography on on silica silica gel gel using using CH CH22Cl22 to afford give a crude, which was purified −−11−1:::1678, 147mg mgof of(2e) (2e)as asbrown browncrystalline crystallineplates. plates.Yield: Yield:25% 25%m.p.: m.p.:140–141 140–141◦°C; °C;IR IR(KBr) (KBr)cm cm 1678,1536, 1536, mg of (2e) as brown crystalline plates. Yield: 25% m.p.: 140–141 IR (KBr) cm 147 C; 1678, 1536, 1H-NMR δ (ppm): 8.61 (d, J = 8.2 Hz, 1H, H-2′′); 00 ); 8.61 0 ); 8.39 1385,1164, 1164,1132, 1132,995, 995,746, 746,598. 598.11H-NMR 8.61(s, (s,1H, 1H,H-2 H-2′); 8.39 1385, 1164, 1132, 995, 746, 598. δ (ppm): (ppm): 8.61 (d, (d, JJ = 8.2 Hz, 1H, H-2 H-2′′); H-2′); 00 0 00 ); (dd,J J==0.9 0.9and and7.5 7.5Hz, Hz,1H, 1H,H-8 H-8′′); 8.23(dd, (dd,J J==2.7 2.7and and6.0 6.0Hz, Hz,1H, 1H,H-4 H-4′); 8.03(d, (d,J J==8.2 8.2Hz, Hz,1H, 1H,H-4′′); H-4′′); H-8′′); H-4′); (dd, ); 8.23 ); 8.03 H-4 07.62 007.46–7.56 7.81(d, (d,JJ===8.1 8.1Hz, Hz,1H, 1H, H-5′′); 7.73 (dd, and 6.4 Hz, 1H, H-7′); (m,(m, 1H, H-3′′); (m, 7.81 and 6.4 Hz, 1H, H-7′); (m, 1H, H-3′′); (m, 8.1 Hz, 1H,H-5′′); H-500 );7.73 7.73(dd, (dd,JJ=J=2.4 =2.4 2.4 and 6.4 Hz, 1H, H-77.62 ); 7.62 1H, H-37.46–7.56 ); 7.46–7.56 13 13 00 00 0 0 13 2H, H-6′′ and H-7′′); 7.26 (m, 2H, H-5′ and H-6′); 4.59 (s, 2H, H-2). C-NMR δ (ppm): 187.4, 137.1, 2H, 2H, H-6′′ andand H-7′′); (m,(m, 2H,2H, H-5′ H-6′); (m, H-6 H-77.26 ); 7.26 H-5and and H-6 4.59 ); 4.59(s,(s,2H, 2H,H-2). H-2). C-NMR C-NMRδδ(ppm): (ppm):187.4, 187.4, 137.1, 137.1, 135.0,134.7, 134.7,133.4, 133.4,132.5, 132.5,131.2, 131.2,130.0, 130.0,129.8, 129.8,128.2, 128.2,128.0, 128.0,127.7, 127.7,126.5, 126.5,125.5, 125.5,124.6, 124.6,123.5, 123.5,123.4, 123.4,117.9, 117.9, 135.0, 123.5, 123.4, 117.9, 113.4and and46.5. 46.5.Elemental Elementalanalysis analysisfor forCCC H 14 BrNO 3 S (428.30 g/mol) calcd.: C: 56.09; H: 3.29; N: 3.27; 113.4 and 46.5. Elemental analysis for 2020 H 14 BrNO 3 S (428.30 g/mol) calcd.: C: 56.09; H: 3.29; N: 3.27; 20 H14 BrNO3 S (428.30 g/mol) calcd.: C: 56.09; H: 3.29; N: 3.27; S: 7.49. Found: C: 55.82; H: 3.59; N: 3.44; S: 7.88. S: 7.49. Found: C: 55.82; H: 3.59; N: 3.44; S: 7.88. 2-Bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone(2f) (2f) 2-Bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone

1385, 1164, 1132, 995, 746, 598. 1H-NMR δ (ppm): 8.61 (d, J = 8.2 Hz, 1H, H-2′′); 8.61 (s, 1H, H-2′); 8.39 (dd, J = 0.9 and 7.5 Hz, 1H, H-8′′); 8.23 (dd, J = 2.7 and 6.0 Hz, 1H, H-4′); 8.03 (d, J = 8.2 Hz, 1H, H-4′′); 7.81 (d, J = 8.1 Hz, 1H, H-5′′); 7.73 (dd, J = 2.4 and 6.4 Hz, 1H, H-7′); 7.62 (m, 1H, H-3′′); 7.46–7.56 (m, 2H, H-6′′ and H-7′′); 7.26 (m, 2H, H-5′ and H-6′); 4.59 (s, 2H, H-2). 13C-NMR δ (ppm): 187.4, 137.1, 135.0, 134.7, 133.4, 132.5, 131.2, 130.0, 129.8, 128.2, 128.0, 127.7, 126.5, 125.5, 124.6, 123.5, 123.4, 117.9, Molecules 2016, 21, 1070 15 of 35 113.4 and 46.5. Elemental analysis for C20H14BrNO3S (428.30 g/mol) calcd.: C: 56.09; H: 3.29; N: 3.27; S: 7.49. Found: C: 55.82; H: 3.59; N: 3.44; S: 7.88. 2-Bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone (2f) 2-Bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone (2f)

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Prepared mmol), p-methoxybenzenesulfonyl p-methoxybenzenesulfonyl Prepared from from 2-bromo-1-(1H-indol-3-yl)ethanone 2-bromo-1-(1H-indol-3-yl)ethanone (1) (1) (894 (894 mg, mg, 3.77 3.77 mmol), chloride chloride (800 (800 mg, mg, 3.77 3.77 mmol), mmol), DMAP DMAP (52 (52 mg, mg, 0.42 0.42 mmol) mmol) and and triethylamine triethylamine (0.63 (0.63 mL, mL, 4.52 4.52 mmol) mmol) to to give a crude, which was purified by column chromatography on silica gel using CH Cl 2 afford 2 to afford 1.35 g give a crude, which was purified by column chromatography on silica gel using CH2Cl2 to ◦ −1 1672, 1537, 1.35 g of as red-brown crystalline 88% m.p.: 189–190 IR (KBr) of (2f) as(2f) red-brown crystalline plates.plates. Yield:Yield: 88% m.p.: 189–190 °C; IR C; (KBr) cm−1: cm 1672,: 1537, 1381, 1 0 0 1381, 996,575. 747,1H-NMR 575. H-NMR δ (ppm): 1H, H-2 8.15 = 7.8 Hz, 1H, H-4 δ (ppm): 8.18 (s,8.18 1H,(s,H-2′); 8.15);(d, J = (d, 7.8JHz, 1H, H-4′); 7.78 );(d,7.78 J= 1170, 1170, 1141, 1141, 996, 747, 0 ); 7.75 (d, J = 9.0 Hz, 2H, H-2” and H-6”); 7.23 (m, 2H, H-50 and H-60 ); 6.79 (d, = 7.8 1H,7.75 H-7(d, 7.8 JHz, 1H,Hz, H-7′); J = 9.0 Hz, 2H, H-2” and H-6”); 7.23 (m, 2H, H-5′ and H-6′); 6.79 (d, J = 9.0 Hz, 00 00 ); 4.43 (s, 2H, H-2); 3.66 (s, 2H, OCH ). 13 C-NMR δ (ppm): 186.9; (d, = 9.0 and Hz, H-5′′); 2H, H-3 H-5H-2); 3 2H,J H-3′′ 4.43and (s, 2H, 3.66 (s, 2H, OCH3). 13C-NMR δ (ppm): 186.9; 164.5; 134.7; 132.4; 164.5; 134.7; 132.4; 129.6 (2C); 128.4; 127.5; 126.1; 125.1; 123.0; 118.0; 114.9 55.8 and 46.0. 129.6 (2C); 128.4; 127.5; 126.1; 125.1; 123.0; 118.0; 114.9 (2C); 113.1; 55.8 and(2C); 46.0.113.1; Elemental analysis Elemental analysis for C H BrNO S (408.27 g/mol) calcd.: C: 50.01; H: 3.46; N: 3.43; S: 7.85. Found: 14 4 for C17H14BrNO4S (408.2717g/mol) calcd.: C: 50.01; H: 3.46; N: 3.43; S: 7.85. Found: C: 49.85; H: 3.61; N: C: 49.85; H: 3.61; N: 3.57; S: 7.59. 3.57; S: 7.59. 2-Bromo-1-(1-(3,5-difluorophenylsulfonyl)-1H-indol-3-yl)ethanone 2-Bromo-1-(1-(3,5-difluorophenylsulfonyl)-1H-indol-3-yl)ethanone(2g) (2g)

Prepared from from 2-bromo-1-(1H-indol-3-yl)ethanone 2-bromo-1-(1H-indol-3-yl)ethanone (1) (1) (1 (1 g, g, 2.41 2.41 mmol), mmol), 3,5-difluorobenzenesulfonyl 3,5-difluorobenzenesulfonyl Prepared chloride (1.07 (1.07 g, g, 5.03 5.03 mmol), mmol), DMAP DMAP (50 (50 mg, mg, 0.41 0.41 mmol) mmol) and and triethylamine triethylamine (1 (1 mL, mL, 7.0 7.0 mmol) mmol) to to give give aa chloride crude, which which was was purified purified by by column column chromatography chromatographyon onsilica silicagel gelusing usingCH CH22Cl Cl22 to 182 mg mg of of crude, to afford afford 182 −1 − 1 (2g) as a pale brown gel. Yield: 18%; m.p.: product in gel state; IR (KBr) cm : 1692, 1392, 1190, 1134, (2g) as a pale brown gel. Yield: 18%; m.p.: product in gel state; IR (KBr) cm : 1692, 1392, 1190, 1134, 0 and 0 ); 7.90 0 ); (bs, (bs, 2H, H-2′ and H-4′); (d, J(d, = 8.2 1H, H-7′); 7.48 1005, 576. 1005, 576. 11H-NMR H-NMRδδ(ppm): (ppm):8.29 8.29 (bs, 2H, H-2 H-47.90 J =Hz, 8.2 Hz, 1H, H-7 7.482H, (bs,H-2′′ 2H, 13C-NMR 00 00 0 0 00 13 and H-6′′); 7.41 (m, 2H, H-5′ and H-6′); 7.03 (t, J = 8.3 Hz, 1H, H-4′′); 4.60 (s, 2H, H-2). H-2 and H-6 ); 7.41 (m, 2H, H-5 and H-6 ); 7.03 (t, J = 8.3 Hz, 1H, H-4 ); 4.60 (s, 2H, H-2). C-NMRδ δ(ppm): (ppm):187.3;163.3 187.3;163.3(dd, (dd,J =J =257.1 257.1and and11.7 11.7Hz, Hz,2C); 2C);140.5 140.5(t, (t,JJ==8.6 8.6Hz, Hz,1C); 1C); 135.0; 135.0; 132.4; 132.4; 127.9; 127.9; 127.1; 127.1; 126.1; 123.7; 123.7; 119.5; 119.5; 113.4; 113.4;111.0 111.0(m, (m,3C); 3C);46.5. 46.5.Elemental Elementalanalysis analysisfor forC16 C16 10 BrF 2NO NO 3S S (414.22 g/mol) 126.1; HH BrF (414.22 g/mol) 10 2 3 calcd.: C: H: 2.43; 2.43; N: N: 3.38; 3.38; S: S: 7.74. 7.74. Found: calcd.: C: 46.39; 46.39; H: Found: C: C: 46.27; 46.27; H: H: 2.61; 2.61; N: N: 3.53; 3.53; S: S: 8.03. 8.03. 4.3.2. General Procedure for 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanone Derivatives (3a–m) 2-(4-(Pyridyl-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone (3a)

(2g) as a pale brown gel. Yield: 18%; m.p.: product in gel state; IR (KBr) cm−1: 1692, 1392, 1190, 1134, 1005, 576. 1H-NMR δ (ppm): 8.29 (bs, 2H, H-2′ and H-4′); 7.90 (d, J = 8.2 Hz, 1H, H-7′); 7.48 (bs, 2H, H-2′′ and H-6′′); 7.41 (m, 2H, H-5′ and H-6′); 7.03 (t, J = 8.3 Hz, 1H, H-4′′); 4.60 (s, 2H, H-2). 13C-NMR δ (ppm): 187.3;163.3 (dd, J = 257.1 and 11.7 Hz, 2C); 140.5 (t, J = 8.6 Hz, 1C); 135.0; 132.4; 127.9; 127.1; Molecules 2016, 21, 1070 113.4; 111.0 (m, 3C); 46.5. Elemental analysis for C16H10BrF2NO3S (414.22 g/mol) 16 of 35 126.1; 123.7; 119.5; calcd.: C: 46.39; H: 2.43; N: 3.38; S: 7.74. Found: C: 46.27; H: 2.61; N: 3.53; S: 8.03. 4.3.2. General Procedure for 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanone 4.3.2. General Procedure for 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanone Derivatives (3a–m) Derivatives (3a–m) 2-(4-(Pyridyl-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone 2-(4-(Pyridyl-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone (3a) (3a)

To aasolution solution 1-(2-pyridyl)-piperazine mg, 0.765 and potassium To of of 1-(2-pyridyl)-piperazine (125(125 mg, 0.765 mmol)mmol) and potassium carbonatecarbonate (106 mg, (106 mg, 0.765 mmol) in (30 mL) 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (300 mg, 0.765 mmol) in acetone (30acetone mL) 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) (300 mg,(2a) 0.765 mmol) 0.765 mmol) was added and the mixture was stirred for 24 h at room temperature. The reaction was was added and the mixture was stirred for 24 h at room temperature. The reaction was stopped stopped by dilution with(30 water (30and mL)the andorganic the organic extracted with 2 (3×× 30 mL). by dilution with water mL) layerlayer was was extracted with CHCH mL). 2 Cl22Cl(3 Molecules 2016, 21, 1070 16 of 33 The combined organic layers were dried with anhydrous sodium sulfate and removal of the solvent under vacuum afforded a crude residue. The solid was purified by column chromatography on The combined organic layers were dried with anhydrous sodium sulfate and removal of the solvent under silica gel (CH2 Cl2 /acetone 9:1) to yield 165 mg of (3a) as orange crystalline plates. Yield: 46% vacuum afforded a crude residue. The solid was purified by column chromatography on silica gel m.p.: 74.9–75.7 ◦ C; IR (KBr) cm−1 : 1664, 1594, 1437, 1379, 1173, 980, 661. 1 H-NMR δ (ppm): 8.62 (CH2Cl2/acetone 9:1) to yield 165 mg of (3a) as orange crystalline plates. Yield: 46% m.p.: 74.9–75.7 °C; IR 0 ), 8.28 (d, J = 6.9 Hz, 1H, H-40 ), 8.14 (d, J = 4.8 Hz, 1H, H-30000 ), 7.88 (d, J = 7.2 Hz, 1H, (s, 1H, H-2 −1: 1664, 1594, 1437, 1379, 1173, 980, 661. 1H-NMR δ (ppm): 8.62 (s, 1H, H-2′), 8.28 (d, J = 6.9 (KBr) cm H-70 ), 7.8 (d, J = 8.3 Hz, 2H, H-200 and H-600 ), 7.46–7.39 (m, 1H, H-50000 ), 7.33–7.24 (m, 2H, H-50 and Hz, 1H, H-4′), 8.14 (d, J = 4.8 Hz, 1H, H-3′′′′), 7.88 (d, J = 7.2 Hz, 1H, H-7′), 7.8 (d, J = 8.3 Hz, 2H, H-60 ), 7.18 (d, J = 7.8 Hz, 2H, H-300 and H-500 ), 6.62–6.54 (m, 2H, H-40000 and H-60000 ), 3.64 (s, 2H, H-2), H-2′′and H-6′′), 7.46–7.39 (m, 1H, H-5′′′′), 7.33–7.24 (m, 2H, H-5′ and H-6′), 7.18 (d, J = 7.8 Hz, 2H, 3.54 (t, J = 4.9 Hz, 4H, H-3000 and H-5000 ), 2.65 (t, J = 4.9 Hz, 4H, H-2000 and H-6000 ), 2.27 (s, 3H, CH3 ). H-3′′and H-5′′), 6.62–6.54 (m, 2H, H-4′′′′ and H-6′′′′), 3.64 (s, 2H, H-2), 3.54 (t, J = 4.9 Hz, 4H, H-3′′′ and 13 C-NMR δ (ppm): 193.6, 159.9, 148.4, 146.4, 138.0, 134.9, 133.3, 130.7 (2C), 128.6, 128.3, 127.6 (2C), H-5′′′), 2.65 (t, J = 4.9 Hz, 4H, H-2′′′ and H-6′′′), 2.27 (s, 3H,CH3). 13C-NMR δ (ppm): 193.6, 159.9, 148.4, 126.2, 125.3, 123.5, 119.7, 113.9, 113.5, 107.6, 67.0, 53.7 (2C), 45.6 (2C) and 22.0. Elemental analysis 146.4, 138.0, 134.9, 133.3, 130.7 (2C), 128.6, 128.3, 127.6 (2C), 126.2, 125.3, 123.5, 119.7, 113.9, 113.5, for C26 H26 N4 O3 S (474.57 g/mol) calcd.: C: 65.80; H: 5.52; N: 11.81; S: 6.76. Found: C: 65.94; H: 5.33; 107.6, 67.0, 53.7 (2C), 45.6 (2C) and 22.0. Elemental analysis for C26H26N4O3S (474.57 g/mol) calcd.: C: N: 11.58; S: 6.63. 65.80; H: 5.52; N: 11.81; S: 6.76. Found: C: 65.94; H: 5.33; N: 11.58; S: 6.63. 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone (3b) 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone (3b)

Prepared from from 1-(2-methoxyphenyl)-piperazine 1-(2-methoxyphenyl)-piperazine (147 mg, 0.765 0.765 mmol), mmol), potassium potassium carbonate carbonate Prepared (147 mg, (106 mg, 0.765 mmol) and 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) (300 mg, 0.765 mmol) to to (106 mg, 0.765 mmol) and 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) (300 mg, 0.765 mmol) give a solid, which was purified by column chromatography on silica gel using CH2Cl2/acetone 9:1 to obtain 255 mg of pure product (3b) as white crystalline plates. Yield: 66% m.p.: 132.3–133.6 °C; IR (KBr) cm−1: 1655, 1374 and 1171, 1244, 755, 742. 1H-NMR δ (ppm): 8.70 (s, 1H, H-2′), 8.31 (d, J = 7.3 Hz, 1H, H-4′), 7.92 (d, J = 7.5 Hz, 1H, H-7′), 7.81 (d, J = 8.1 Hz, 2H, H-2′′ and H-6′′), 7.36–7.29 (m, 2H, H-5′ and H-6′), 7.22 (d, J = 8.1 Hz, 2H, H-3′′ and H-5′′), 7.01–6.90 (m, 3H, H-3′′′, H-4′′′ and H-5′′′), 6.84 (d, J

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Prepared from 1-(2-methoxyphenyl)-piperazine (147 mg, 0.765 mmol), potassium carbonate (106 mg, 0.765 mmol) and 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) (300 mg, 0.765 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 give a solid, which was purified by column chromatography on silica gel using CH2Cl 2/acetone 9:1 to to obtain 255 mg of pure product (3b) as white crystalline plates. Yield: 66% m.p.: 132.3–133.6 ◦ C; IR obtain 2551 mg of pure product (3b) as white crystalline plates. Yield: 66% m.p.: 132.3–133.6 °C; IR (KBr) cm− 1655, 1374 and 1171, 1244, 755, 742. 11 H-NMR δ (ppm): 8.70 (s, 1H, H-20 ), 8.31 (d, J = 7.3 Hz, −1: :1655, (KBr) cm 1374 and 1171, 1244, 755, 742. H-NMR δ (ppm): 8.70 (s, 1H, H-2′), 8.31 (d, J = 7.3 Hz, 1H, H-40 ), 7.92 (d, J = 7.5 Hz, 1H, H-70 ), 7.81 (d, J = 8.1 Hz, 2H, H-200 and H-600 ), 7.36–7.29 (m, 2H, H-50 1H, H-4′), 7.92 (d, J = 7.5 Hz, 1H, H-7′), 7.81 (d, J = 8.1 Hz, 2H, H-2′′ and H-6′′), 7.36–7.29 (m, 2H, H-5′ and H-60 ), 7.22 (d, J = 8.1 Hz, 2H, H-300 and H-500 ), 7.01–6.90 (m, 3H, H-3000 , H-4000 and H-5000 ), 6.84 (d, and H-6′), 7.22 (d, J000= 8.1 Hz, 2H, H-3′′ and H-5′′), 7.01–6.90 (m, 3H, H-3′′′, H-4′′′ and H-5′′′), 6.84 (d, J J = 7.7 Hz, 1H, H-6 ), 3.84 (s, 3H, O-CH3 ), 3.71 (s, 2H, H-2), 3.13 (bs, 4H, H-30000 and H-50000 ), 2.80 (bs, = 7.7 Hz,0000 1H, H-6′′′),0000 3.84 (s, 3H, O-CH3), 3.71 (s, 2H, H-2), 3.13 (bs, 4H, H-3′′′′ and H-5′′′′), 2.80 (bs, 4H, 13 C-NMR δ (ppm): 193.2, 152.3, 145.9, 141.1, 134.6, 134.5, 4H, H-2 and H-6 ), 2.31 (s, 3H, CH 3 ). H-2′′′′ and H-6′′′′), 2.31 (s, 3H, CH3). 13C-NMR δ (ppm): 193.2, 152.3, 145.9, 141.1, 134.6, 134.5, 133.0, 133.0, 130.3127.9, (2C), 127.9, 127.2 125.7, (2C), 125.7, 130.3 (2C), 127.2 (2C), 124.9,124.9, 123.1,123.1, 123.0,123.0, 121.0,121.0, 119.3,119.3, 118.3,118.3, 113.1,113.1, 111.3,111.3, 66.6, 66.6, 55.4, 55.4, 53.7 53.7 (2C), 50.5 (2C) and 21.6. Elemental analysis for C H N O S (503.61 g/mol) calcd.: C: H: 28 29 3 4 (2C), 50.5 (2C) and 21.6. Elemental analysis for C28H29N3O4S (503.61 g/mol) calcd.: C: 66.78; H:66.78; 5.80; N: 5.80; N: 8.34; S: 6.37. Found: C: 66.55; H: 5.97; N: 8.21; S: 6.75. 8.34; S: 6.37. Found: C: 66.55; H: 5.97; N: 8.21; S: 6.75. 2-(4-(Pyrimidin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone 2-(4-(Pyrimidin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanone (3c) (3c)

Prepared from 1-(2-pyrimidyl)-piperazine 1-(2-pyrimidyl)-piperazine (84 (84 mg, mg, 0.512 0.512 mmol), mmol), potassium potassium carbonate carbonate (70 (70 mg, mg, 0.512 mmol) and 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone (2a) (200 mg, 0.512 mmol) to give a solid, mmol) and 2-bromo-1-(1-tosyl-1H-indol-3-yl)ethanone give a solid, Molecules 2016, 21, 1070 17 of 33 which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 to obtain ◦ C; IR (KBr) cm−1 : 221 mgwas of pure product as white crystalline plates. Yield:gel 91%; m.p.:CH 133–134 which purified by (3c) column chromatography on silica using 2Cl2/acetone 9:1to obtain 1 0 1651, 1586, 1378,product 1173, 571. H-NMR δ (ppm): 8.72 (s, 1H, H-291%; ); 8.35 (d, 133–134 J = 7.1 Hz, H-40 );cm 8.31 −1: 221 mg of pure (3c) as white crystalline plates. Yield: m.p.: °C;1H, IR (KBr) 000 000 0 00 and (d, J = 4.8 Hz, 2H, H-4 and H-6 ); 7.95 (d, J = 7.6 Hz, 1H, H-7 ); 7.84 (d, J = 8.3 Hz, 2H, H-2 1651, 1586, 1378, 1173, 571. 1H-NMR δ (ppm): 8.72 (s, 1H, H-2′); 8.35 (d, J = 7.1 Hz, 1H, H-4′); 8.31 (d, 00 7.35 (m, 2H, H-50 and H-60 ); 7.25 (d, J = 8.2 Hz, 2H, H-300 and H-500 ); 6.49 (t, J = 4.7 Hz, 1H, JH-6 = 4.8);Hz, 2H, H-4′′′ and H-6′′′); 7.95 (d, J = 7.6 Hz, 1H, H-7′); 7.84 (d, J = 8.3 Hz, 2H, H-2′′ and H-6′′); 0000 0000 ); 3.71 (s, 2H, H-2); 2.66 (t, J = 5.0 Hz, 4H, H-20000 H-5000 ); 3.90 (t, J =and 4.9H-6′); Hz, 4H, H-52H, 7.35 (m, 2H, H-5′ 7.25H-3 (d, J = and 8.2 Hz, H-3′′ and H-5′′); 6.49 (t, J = 4.7 Hz, 1H, H-5′′′); 3.90 0000 ); 2.33 (s, 3H, CH ). 13 C-NMR δ (ppm): 193.5, 162.0, 158.1 (2C), 146.4, 135.0, 134.9, 133.3, and 3 (t, J =H-6 4.9 Hz, 4H, H-3′′′′ and H-5′′′′); 3.71 (s, 2H, H-2); 2.66 (t, J = 5.0 Hz, 4H, H-2′′′′ and H-6′′′′); 2.33 (s, 130.7 (2C), 128.3, 127.5 (2C), 126.1, 125.3, 123.5, 119.8, 113.5, 110.4, 67.0, 53.8 (2C), 44.0 (2C) and 22.0. 3H, CH 3). 13C-NMR δ (ppm): 193.5, 162.0, 158.1 (2C), 146.4, 135.0, 134.9, 133.3, 130.7 (2C), 128.3, 127.5 (2C), Elemental analysis for C113.5, N5 O367.0, S (475.56 g/mol) C: 22.0. 63.14; H: 5.30; N: 14.73;for S: 6.74. 25 H25110.4, 126.1, 125.3, 123.5, 119.8, 53.8 (2C), 44.0calcd.: (2C) and Elemental analysis C25H25Found: N5O3S C: 62.75; H: 5.11; N: 14.35; S: 6.66. (475.56 g/mol) calcd.: C: 63.14; H: 5.30; N: 14.73; S: 6.74. Found: C: 62.75; H: 5.11; N: 14.35; S: 6.66. 1-(1-(4-Chlorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone 1-(1-(4-Chlorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone (3d) (3d)

Prepared from 1-(2-pyrimidyl)-piperazine (100 mg, 0.640 mmol), potassium carbonate (90 mg, 0.640 mmol) and 2-bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone (2b) (263 mg, 0.640 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2Cl2/acetone 4:1 to obtain 281 mg of pure product (3d) as white crystalline plates. Yield: 89% m.p.: 168–169 °C; IR (KBr) cm−1: 1666, 1587, 1387, 1168, 760, 569. 1H-NMR δ (ppm): 8.72 (s, 1H, H-2′); 8.36

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1-(2-pyrimidyl)-piperazine (100 Prepared from 1-(2-pyrimidyl)-piperazine (100 mg, mg, 0.640 0.640 mmol), mmol), potassium potassium carbonate carbonate (90 (90 mg, mg, 2-bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone (2b) 0.640 mmol) and 2-bromo-1-(1-(4-chlorophenylsulfonyl)-1H-indol-3-yl)ethanone (2b) (263 (263 mg, mg, 0.640 mmol) to give a solid, which was purified by column chromatography on silica gel using CH22Cl22/acetone /acetone4:1 4:1totoobtain obtain281 281mg mgof ofpure pureproduct product(3d) (3d)as aswhite whitecrystalline crystalline plates. plates. Yield: Yield: 89% 89% m.p.: m.p.: 0 ); 8.36 H-2′); (KBr) cm cm−−11::1666, 168–169 ◦°C; C; IR (KBr) 1666,1587, 1587, 1387, 1387, 1168, 1168, 760, 760, 569. 11H-NMR H-NMR δδ (ppm): 8.72 8.72 (s, 1H, H-2 0 ); 8.31 000 and H-6′′′); 1H, H-4 H-4′); 8.31 (d, (d, JJ == 4.8, 2H, H-4 H-4′′′ (dd, J = 6.7 and 2.1 Hz, 1H, H-6000 ); 7.92 7.92 (dd, (dd, JJ ==7.0 7.0and and 1.6 1.6 Hz, Hz, 1H, 1H, 0 00 00 H-7′); H-2′′ and H-6′′); H-7 ); 7.87 (d, J = 8.7 Hz, 2H, H-2 H-6 ); 7.41 7.41 (d, (d, J == 8.7 8.7 Hz, Hz, 2H, 2H, H-3′′ H-300 and and H-5′′); H-500 );7.39–7.34 7.39–7.34 (m, (m, 2H, 2H, H-5′0 and 4.94.9 Hz, 4H, H-3′′′′ and H-5′′′′); 3.72 (s, 2H, HH-5 and H-6′); H-60 ); 6.49 6.49 (t, (t, JJ==4.7 4.7Hz, Hz,1H, 1H,H-5′′′); H-5000 );3.91 3.91(t,(t,J =J = Hz, 4H, H-30000 and H-50000 ); 3.72 (s, 2H, 0000 0000 13 13 2); 2.67 (t, (t, J =J 5.0 Hz, δ (ppm): H-2); 2.67 = 5.0 Hz,4H, 4H,H-2′′′′ H-2 and andH-6′′′′). H-6 ). C-NMR C-NMR δ (ppm):193.5, 193.5,162.0, 162.0,158.1 158.1(2C), (2C),141.8, 141.8, 136.2, 136.2, 134.8, 133.0, 130.4 (2C), 128.9 (2C), 128.4, 126.4, 125.6, 123.6, 120.2, 113.3, 110.4, 67.1, 53.8 (2C) and 44.1 analysis for for CC24 24H22 22ClN (2C). Elemental analysis ClN55OO3S (495.98g/mol) g/mol)calcd.: calcd.:C:C:58.12; 58.12;H: H:4.47; 4.47;N: N:14.12; 14.12;S: S: 6.46. 6.46. 3 S(495.98 Found: C: 58.07; H: 4.40; N: 14.27; S: 6.59. 1-(1-(4-Fluorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone (3e) (3e) 1-(1-(4-Fluorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone

Prepared from 1-(2-pyrimidyl)-piperazine (83 mg, 0.506 mmol), potassium carbonate (70 mg, Prepared from 1-(2-pyrimidyl)-piperazine (83 mg, 0.506 mmol), potassium carbonate (70 mg, 0.506 mmol) and 2-bromo-1-(1-(4-fluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2c) (200 mg, 0.506 mmol) and 2-bromo-1-(1-(4-fluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2c) (200 mg, 0.506 mmol) to give a solid, which was purified by column chromatography on silica gel using 0.506 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 to obtain 187 mg of pure product (3e) as white crystalline plates. Yield: 77% m.p.: 145–146 ◦ C; IR (KBr) cm−1 : 1666, 1587, 1386, 1172, 1186, 571. 1 H-NMR δ (ppm): 8.71 (s, 1H, H-20 ), 8.37 (d, J = 7.2 Hz, 1H, H-40 ); 8.32 (d, J = 4.8 Hz, 2H, H-4000 and H-6000 ); 7.98 (dd, J = 8.7 and 4.9 Hz, 2H, H-200 and H-600 ); 7.93 (d, J = 7.6, 1H, H-70 ); 7.42–7.33 (m, 2H, H-50 and H-60 ); 7.16 (t, J = 8.4 Hz, 2H, H-300 and H-500 ); 6.50 (t, J = 4.7 Hz, 1H, H-5000 ); 3.91 (t, J = 4.9 Hz, 4H, H-30000 and H-50000 ); 3.72 (s, 2H, H-2); 2.67 (t, J = 4.9 Hz, 4H, H-20000 and H-60000 ). 13 C-NMR δ (ppm): 193.5, 166.5 (d, J = 258.8 Hz, 1C); 162.0, 158.1 (2C), 134.8, 133.9 (d, J = 3.2 Hz, 1C), 133.0, 130.4 (d, J = 9.8 Hz, 2C), 128.3, 126.4, 125.5, 123.6, 120.1, 117.6 (d, J = 23.0 Hz, 2C), 113.3, 110.5, 67.1, 53.8 (2C) and 44.1 (2C). Elemental analysis for C24 H22 FN5 O3 S (479.53 g/mol) calcd.: C: 60.11; H: 4.62; N: 14.60; S: 6.69. Found: C: 59.92; H: 4.45; N: 14.80; S: 6.83.

(d, J = 7.2 Hz, 1H, H-4′); 8.32 (d, J = 4.8 Hz, 2H, H-4′′′ and H-6′′′); 7.98 (dd, J = 8.7 and 4.9 Hz, 2H, H-3′′ and H-5′′); 6.50 (t, J = 4.7 Hz, 1H, H-5′′′); 3.91 (t, J = 4.9 Hz, 4H, H-3′′′′ and H-5′′′′); 3.72 (s, 2H, H-2′′ and H-6′′); 7.93 (d, J = 7.6, 1H, H-7′); 7.42–7.33 (m, 2H, H-5′ and H-6′); 7.16 (t, J = 8.4 Hz, 2H, H-2); 2.67 (t, J = 4.9 Hz, 4H, H-2′′′′ and H-6′′′′). 13C-NMR δ (ppm): 193.5, 166.5 (d, J = 258.8 Hz, 1C); H-3′′ and H-5′′); 6.50 (t, J = 4.7 Hz, 1H, H-5′′′); 3.91 (t, J = 4.9 Hz, 4H, H-3′′′′ and H-5′′′′); 3.72 (s, 2H, 162.0, 158.1 (2C), 134.8, 133.9 (d, J = 3.2 Hz, 1C), 133.0, 130.4 (d, J = 9.8 Hz, 2C), 128.3, 126.4, 125.5, H-2); 2.67 (t, J = 4.9 Hz, 4H, H-2′′′′ and H-6′′′′). 13C-NMR δ (ppm): 193.5, 166.5 (d, J = 258.8 Hz, 1C); 123.6, 120.1, 117.6 (d, J = 23.0 Hz, 2C), 113.3, 110.5, 67.1, 53.8 (2C) and 44.1 (2C). Elemental analysis for 162.0, 158.1 (2C), 134.8, 133.9 (d, J = 3.2 Hz, 1C), 133.0, 130.4 (d, J = 9.8 Hz, 2C), 128.3, 126.4, 125.5, Molecules 2016, 1070 19 ofN: 35 C24H22FN 5O321, S (479.53 g/mol) calcd.: C: 60.11; H: 4.62; N: 14.60; S: 6.69. Found: C: 59.92; H: 4.45; 123.6, 120.1, 117.6 (d, J = 23.0 Hz, 2C), 113.3, 110.5, 67.1, 53.8 (2C) and 44.1 (2C). Elemental analysis for 14.80; S: 6.83. C24H22FN5O3S (479.53 g/mol) calcd.: C: 60.11; H: 4.62; N: 14.60; S: 6.69. Found: C: 59.92; H: 4.45; N: 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone (3f) 14.80; S: 6.83. 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone (3f) 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone (3f)

Prepared from 1-(2-pyridyl)-piperazine (97 mg, 0.595 mmol), potassium carbonate (83 mg, Prepared from 1-(2-pyridyl)-piperazine (97 mg, 0.595 mmol), potassium carbonate (83 mg, 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, 0.595 mmol) (97 mg, 0.595 mmol), potassium carbonate (83 mg, 0.595Prepared mmol) from and 1-(2-pyridyl)-piperazine 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, to obtain a crude which was purified by column chromatography employing CH2Cl2/acetone 9:1 to yield 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, 0.595 mmol) 0.595 mmol) to obtain a crude which was purified by column chromatography employing 324 mg of (3f) as light yellow crystalline plates. Yield: 93% m.p.: 179–180 °C; IR (KBr) cm−1: 1671, 1593, to obtain a crude which was purified by column chromatography employing CH 2Cl2/acetone 9:1 to yield CH Cl /acetone 9:1 to yield 324 mg of (3f) as light yellow crystalline plates. Yield: 93% m.p.: 2 2 and 2.7 Hz, 1479, 1434, 1396, 1163, 1136, 604, 568. 1H-NMR δ (ppm): 8.68 (s, 1H, H-2′); 8.36 (dd,1 J = 6.1 −1 :982, 324 mg of◦ C; (3f) lightcm yellow crystalline plates.1434, Yield:1396, 93%1163, m.p.: 1136, 179–180 °C; IR 568. (KBr) H-NMR cm−1: 1671, 1593, 179–180 IRas(KBr) 1671, 1593, 1479, 982, 604, δ (ppm): 1H, H-4′); 8.22 (dd, J = 4.9 and 1.2 Hz, 1H, 1H-3′′′); 7.93 (dd,0 J = 6.4 and 2.4, 1H, H-7′); 7.84 (d, J = 8.7 000 Hz, 2H, (ppm): 8.68(dd, (s, 1H, 8.36 = 6.1H-3 and 2.7 Hz, 1479, 1434, 1163, 604, 568.2.7H-NMR 8.68 (s, 1H,1396, H-20 ); 8.361136, (dd, 982, J = 6.1 and Hz, 1H,δH-4 ); 8.22 J = H-2′); 4.9 and 1.2(dd, Hz,J 1H, ); 7.93 H-2′′ and H-6′′); 7.64 (d, J =0 8.7 Hz, 2H, H-3′′ and H-5′′);00 7.51 (td, 00J = 8.9, 7.2 and 2.0 Hz, 1H, H-5′′′); 00 1H, H-4′); = 4.9H-7 and);1.2 Hz, 6.4 and 1H, (d, H-7′); (d, J2H, = 8.7 Hz, and 2H, (dd, J = 6.48.22 and(dd, 2.4,J1H, 7.84 (d,1H, J =H-3′′′); 8.7 Hz,7.93 2H,(dd, H-2J =and H-6 2.4, ); 7.64 J = 7.84 8.7 Hz, H-3 7.35–7.43 (m, 2H, H-5′ and H-6′); 6.63–6.70 (m, 2H, H-4′′′ and H-6′′′); 3.70 (s, 2H, H-2); 3.62 (t, J = 5.0 Hz, 4H, 00 000 0 0 H-2′′ and H-6′′); 7.64 (d, J = 8.7 Hz, 2H, H-3′′ and H-5′′); 7.51 (td, J = 8.9, 7.2 and 2.0 Hz, 1H, H-5′′′); H-5 ); 7.51 (td, J = 8.9, 7.2 and 2.0 Hz, 1H, H-5 ); 7.35–7.43 13(m, 2H, H-5 and H-6 ); 6.63–6.70 (m, 2H, H-3′′′′ and H-5′′′′); 2.72 (t, J = 5.0 Hz, 4H, H-2′′′′ and H-6′′′′). C-NMR δ (ppm): 193.5, 159.9, 148.4, 139.4 000 H-5′ 7.35–7.43 (m, 2H, and 6.63–6.70 H-4′′′ (s,H-5 2H,0000 H-2); 3.62(t,(t,J J== 5.0 5.0 Hz, 4H, H-4000 and H-6 ); 3.70 (s,H-6′); 2H, H-2); 3.62 (m, (t, J2H, = 5.0 Hz,and 4H,H-6′′′); H-300003.70 and ); 2.72 4H, (2C),0000 138.0, 137.5,0000134.8, 133.0, 128.6 (2C), 128.4, 126.4, 125.6, 123.7, 120.2, 114.0, 113.4, 107.6, 103.2, 67.2, 53.8 13C-NMR δ (ppm): 193.5, 159.9, 148.4, 139.4 13 C-NMR H-3′′′′ (t, J = 5.0 Hz, 4H,193.5, H-2′′′′159.9, and H-6′′′′). H-2 and andH-5′′′′); H-6 ).2.72 δ (ppm): 148.4, 139.4 (2C), 138.0, 137.5, 134.8, 133.0, 128.6 (2C) and 45.7 (2C). Elemental analysis for C25H23IN4O3S (586.44 g/mol) calcd.: C: 51.20; H: 3.95; N: 9.55; (2C), 138.0, 128.6 (2C), 128.4, 126.4, 125.6,103.2, 123.7,67.2, 120.2, 114.0, 113.4, 103.2,Elemental 67.2, 53.8 128.4,137.5, 126.4,134.8, 125.6,133.0, 123.7, 120.2, 114.0, 113.4, 107.6, 53.8 (2C) and 107.6, 45.7 (2C). S: 5.47. Found: C: 51.32; H: 3.82; N: 9.92; S: 5.20. (2C) and for 45.7C(2C). analysis for C25calcd.: H23IN4C: O3S51.20; (586.44 g/mol) 51.20; H: 3.95; N: 9.55; analysis IN4 O3 S (586.44 g/mol) H: 3.95; N:calcd.: 9.55; S:C:5.47. Found: C: 51.32; H: 25 H23Elemental 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanone (3g) S: 5.47. 51.32; H: 3.82; N: 9.92; S: 5.20. 3.82; N:Found: 9.92; S: C: 5.20. 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanone (3g) 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanone (3g) H4''' 3''' H

H O3'''

H5' 5' H H6'

H6'

H4'''

H5'''

H5'''' H5''' H6''' H5'''' N H3'''' O 6'''' HH5'''' H3'''' H6''' 5'''' H H6'''' NN 3'''' HH2'''' O 6'''' 2'''' H H3'''' H H4' H2 H6'''' H N2 H2'''' O H2'''' H4' H2'H2 N H2 O 2' S 7' H 6'' H O H N 2'' H O H7' O S H6''H5'' 3'' H H2''

I

H5''

3''

H

I

Prepared from 1-(2-methoxyphenyl)-piperazine (114 mg, 0.595 mmol), potassium carbonate (82 mg, 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, 0.595 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 to give 358 mg of (3g) as orange crystalline plates. Yield: 98% m.p.: 182–183 ◦ C; IR (KBr) cm−1 : 1655, 1385, 1172, 741, 603, 570. 1 H-NMR δ (ppm): 8.72 (s, 1H, H-20 ); 8.36 (dd, J = 6.4 and 2.6 Hz, 1H, H-40 ); 7.93 (dd, J = 6.6 and 2.2 Hz, 1H, H-70 ); 7.82 (d, J = 8.6 Hz, 2H, H-200 and H-600 ); 7.64 (d, J = 8.6 Hz, 2H, H-300 and H-500 ); 7.35–7.41 (m, 2H, H-50 and H-60 ); 7.05–7.00 (m, 1H, H-5000 ); 6.99–6.94 (m, 2H, H-3000 and H-4000 ); 6.88 (d, J = 7.7 Hz, 1H, H-6000 ); 3.87 (s, 3H, OCH3 ); 3.71 (s, 2H, H-2);

(82 mg, 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, mg,chromatography 0.595 mmol), potassium 0.595Prepared mmol) tofrom give 1-(2-methoxyphenyl)-piperazine a solid, which was purified by (114 column on silica carbonate gel using (82 2mg, 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 CH Cl2/acetone 9:1 to give 358 mg of (3g) as orange crystalline plates. Yield: 98% m.p.: 182–183 °C;mg, IR 1H-NMRby 0.595 mmol) to give solid,741, which column8.72 chromatography on (dd, silicaJ gel 1385,a 1172, 603,was 570. purified δ (ppm): (s, 1H, H-2′); 8.36 = 6.4using and (KBr) cm−1: 1655, CHHz, 2Cl2/acetone 9:17.93 to give of (3g) orange crystalline plates. Yield: 98%H-2′′ m.p.:and 182–183 °C; IR 2.6 1H, H-4′); (dd,358 J = mg 6.6 and 2.2as Hz, 1H, H-7′); 7.82 (d, J = 8.6 Hz, 2H, H-6′′); 7.64 Molecules 2016, 21, 1070 20 of 35 −1 1 1655,2H, 1385, 1172, 741, 603, 570. H-NMR (ppm): 1H, H-2′); 8.36 (m, (dd, 1H, J = 6.4 and (KBr) (d, J =cm 8.6: Hz, H-3′′ and H-5′′); 7.35–7.41 (m, δ2H, H-5′8.72 and(s,H-6′); 7.05–7.00 H-5′′′); 2.6 Hz, 1H, H-4′); 6.6 and 2.2(d, Hz,J 1H, 7.82 H-6′′′); (d, J = 8.6 H-6′′); 6.99–6.94 (m, 2H, 7.93 H-3′′′(dd, andJ =H-4′′′); 6.88 = 7.7H-7′); Hz, 1H, 3.87Hz, (s, 2H, 3H,H-2′′ OCHand 3); 3.71 (s, 7.64 2H, 0000 0000 0000 0000 13 13 (d, J(bs, =3.15 8.6 Hz, 2H,H-3′′′′ H-3′′ andH-5′′′′); 7.35–7.41 2H, H-5′H-6′′′′). H-6′); (m, 193.8, 1H, H-2); (bs, 4H, and 2.81 (bs, 4H,(m, H-2′′′′ and C-NMR δ (ppm): 152.7, 3.15 4H, H-3 and H-5 ); H-5′′); 2.81 (bs, 4H, H-2 and H-6 ).and C-NMR δ7.05–7.00 (ppm): 193.8, 152.7,H-5′′′); 139.4 6.99–6.94 2H,133.2, H-3′′′128.6 and (2C), H-4′′′); 6.88 (d, J 125.6, = 7.7 Hz, 1H, H-6′′′); 3.87 (s,121.5, 3H, OCH 3); 118.7, 3.71 2H, 139.4 (2C),(m, 137.6, 134.9, 133.2, 128.6 (2C), 128.4, 126.4, 125.6, 123.7, 123.6, 120.3, 113.4, (2C), 137.6, 134.9, 128.4, 126.4, 123.7, 123.6, 121.5, 120.3, 118.7, 113.4, 111.8,(s, 103.2, 13C-NMR δ (ppm): 193.8, 152.7, H-2); 3.15 (bs, 4H, H-3′′′′ and H-5′′′′); 2.81 (bs, 4H, H-2′′′′ and H-6′′′′). 111.8,55.8, 103.2, 54.2 (2C). (2C) Elemental and 51.1 (2C). Elemental analysis C27H26g/mol) IN3O4S calcd.: (615.48C:g/mol) 67.3, 54.267.3, (2C)55.8, and 51.1 analysis for C27 H S (615.48 52.69; 26 IN3 O4for 139.4 (2C), 137.6, 133.2, (2C), 126.4, 123.7, 123.6, 121.5, 120.3, 118.7, 113.4, calcd.: C:N:52.69; H: 4.26; Found: N: 6.83;128.6 S: 52.60; 5.21. Found: 52.60; H: 4.21; N: 6.80; S: 4.97. H: 4.26; 6.83; S: 134.9, 5.21. C: H:128.4, 4.21;C:N: 6.80;125.6, S: 4.97. 111.8, 103.2, 67.3, 55.8, 54.2 (2C) and 51.1 (2C). Elemental analysis for C27H26IN3O4S (615.48 g/mol) 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone (3h) (3h) 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone calcd.: C: 52.69; H: 4.26; N: 6.83; S: 5.21. Found: C: 52.60; H: 4.21; N: 6.80; S: 4.97. 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone (3h)

Prepared from 1-(2-pyrimidyl)-piperazine (100 mg, 0.595 mmol), potassium carbonate (82 mg, Prepared from 1-(2-pyrimidyl)-piperazine (100 mg, 0.595 mmol), potassium carbonate 0.595 mmol) and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, 0.595 mmol) (82 mg, 0.595 mmol)1-(2-pyrimidyl)-piperazine and 2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone (2d) (300 mg, Prepared (100 mg, 0.595 mmol), carbonate (82 mg, to give a solid, from which was purified by column chromatography on silicapotassium gel using CH 2Cl2/acetone 9:1 0.595 mmol)and to give a solid, which was purified by column chromatography on mg, silica gel using 0.595 mmol) 0.595 to obtain 334 mg2-bromo-1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)ethanone of (3h) as white crystalline plates. Yield: 96% m.p.: 184–185(2d) °C;(300 IR (KBr) cm−1mmol) : 1667, CH 9:1 towas obtain 334 mg (3h) aschromatography white crystallineonplates. Yield: 96%CH m.p.: 184–185 ◦9:1 C; 2 Cl2a/acetone 1H-NMR to give solid, which purified by of column silica gel using 2Cl 2/acetone δ (ppm): 8.68 (s, 1H, H-2′); 8.36 (dd, J = 6.3 and 2.5 Hz, 1H,0 H-4′); 1587, 1386, 1169, 981, 740, 569. − 1 1 IR (KBr) cm : 1667, 1587, 1386,crystalline 1169, 981,plates. 740, 569. H-NMR δ 184–185 (ppm): 8.68 (s,(KBr) 1H, H-2 8.36 −1); to obtain (3h) as white 96% IR cmHz, : 1667, 8.2 (d, J =,334 4.7 mg Hz,of 2H, H-4′′′ and0 H-6′′′); 7.91, (dd, J =Yield: 6.6 and 2.2m.p.: Hz, 1H, H-7′);°C; 7.82 (d, J = 8.7 2H, 000 and H-6000 ); 7.91, (dd, J = 6.6 and 2.2 Hz, (dd, J = 6.3 and 2.5 Hz, 1H, H-4 ); 8.2 (d, J =, 4.7 Hz, 2H, H-4 1 H-NMR δ (ppm): 8.68 (s,7.38 1H,(m, H-2′); 8.36 (dd, JH-6′); = 6.3 and 2.5 Hz, 1H, H-4′); 1587, and 1386,H-6′′); 1169,7.63 981,(d, 740, 569. H-2′′ J = 8.7 Hz, 2H, H-3′′ and H-5′′); 2H, H-5′ and 6.50 (t, J = 4.7 Hz, 1H, 00 ); 7.63 (d, J = 8.7 Hz, 2H, H-300 and H-500 ); 7.38 (m, 2H, 1H, H-7J 0=, ); 7.82 (d, J2H, = 8.7 Hz,and 2H, H-6′′′); H-200 and H-6 8.2 (d, 4.7 Hz, H-4′′′ 7.91, (dd, J = 6.6 and 2.2 Hz, 1H, H-7′); 7.82 (d, J = 8.7 Hz, 2H, H-5′′′); 3.91 (t, J = 4.9 Hz, 4H, H-3′′′′ and H-5′′′′); 3.70 (s, 2H, H-2); 2.67 (t, J = 5.0 Hz, 4H, H-2′′′′ and H-6′′′′). 0 and H-60 ); 6.50 (t, J = 4.7 Hz, 1H, H-5000 ); 3.91 (t, J = 4.9 Hz, 4H, H-30000 and H-50000 ); 3.70 (s, 2H, H-5 13 H-2′′ and H-6′′); 7.63193.5, (d, J =162.0, 8.7 Hz, 2H,(2C), H-3′′139.4 and H-5′′); 7.38 (m, 2H, H-5′ H-6′); 6.50 (t, J =126.4, 4.7 Hz, 1H, C-NMR δ (ppm): 158.2 (2C), 137.5, 134.8, 132.9,and 128.6 (2C), 128.4, 125.6, 0000 and H-60000 ). 13 C-NMR δ (ppm): 193.5, 162.0, 158.2 (2C), 139.4 (2C), H-2); H-2 H-5′′′);2.67 3.91(t,(t,J113.3, J==5.0 4.9Hz, Hz, 4H, 4H, H-3′′′′67.1, and 53.8 H-5′′′′); 3.70 (s, 2H, (t, J = 5.0analysis Hz, 4H, for H-2′′′′ H-6′′′′). 123.7, 120.3, 110.5, 103.3, (2C) and 44.1H-2); (2C).2.67 Elemental C24and H22IN 5O3S 137.5, 134.8, 132.9, 128.6 (2C), 128.4, 126.4, 125.6, 120.3,134.8, 113.3, 110.5, 128.6 103.3,(2C), 67.1,128.4, 53.8 (2C) and 44.1 13C-NMR δ (ppm): 193.5, 162.0, 158.2 (2C), 139.4 123.7, (2C), 137.5, 125.6, (587.43 g/mol) calcd.: C: 49.07; H: 3.77; N: 11.92; S: 5.46. Found: C:132.9, 49.11; H: 3.71; N: 12.09;126.4, S: 5.50. (2C). analysis C24 H (587.43 calcd.: C: 49.07;analysis H: 3.77;for N: C 11.92; S: 5.46. 22 IN53.8 5 O3 S(2C) 123.7,Elemental 120.3, 113.3, 110.5,for 103.3, 67.1, andg/mol) 44.1 (2C). Elemental 24H22IN5O3S 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone (3i) Found: C: 49.11; H: 3.71; N: 12.09; S: 5.50. (587.43 g/mol) calcd.: C: 49.07; H: 3.77; N: 11.92; S: 5.46. Found: C: 49.11; H: 3.71; N: 12.09; S: 5.50. 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanone(3i) (3i)

Prepared from 1-(2-pyridyl)-piperazine (27 mg, 0.163 mmol), potassium carbonate (23 mg, 0.163 mmol) and 2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) (70 mg, 0.163 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 to obtain 71 mg of (3i) as white crystalline plates. Yield: 86%; m.p.: 76–77 ◦ C; IR (KBr) cm−1 : 1664, 1593, 1437, 1371, 1169, 1133, 769. 1 H-NMR δ (ppm): 8.96 (s, 1H, H-20 ); 8.65

Molecules 2016, 2016, 21, 21, 1070 1070 Molecules

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Prepared from 1-(2-pyridyl)-piperazine (27 mg, 0.163 mmol), potassium carbonate (23 mg, 0.163 mmol) and 2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) (70 mg, 0.163 mmol) Molecules 2016, 21, 1070 21 of 35 to give a solid, which was purified by column chromatography on silica gel using CH22Cl22/acetone 9:1 −1 to obtain 71 mg of (3i) as white crystalline plates. Yield: 86%; m.p.: 76–77 °C; IR (KBr) cm−1 : 1664, 1593, 00 00 0 1 1H-NMR 1H, H-8 (d, J =1371, 8.6 Hz, 1H,1133, H-2 769. ); 8.38 (dd, J =δ7.5 and 1.0 8.34(d, (dd, = 6.2 and Hz, 1H, (ppm): 8.96Hz, (s, 1H, H-2′););8.65 J =J 8.6 Hz, 1H,2.9 H-2′′); 8.38H-4 (dd,); 1437, 1169, 000 00 00 J8.22 = 7.5 andJ =1.0 1H, 8.34H-3 (dd,);J 8.04 = 6.2(d, and (dd, 1H,); (dd, 4.8Hz, and 1.0H-8′′); Hz, 1H, J =2.9 8.2Hz, Hz,1H, 1H,H-4′); H-4 8.22 ); 7.84 (d,J J==4.8 8.1and Hz,1.0 1H,Hz, H-5 0 00 000 7.81 (dd, 3.1 1H, Hz, H-4′′); 1H, H-7 7.60 ); 7.567.81 (t, J(dd, = 7.8 1H, 3.1 H-5Hz,);1H, 7.53–747 H-3′′′); 8.04J = (d,6.3 J =and 8.2 Hz, 7.84); (d, J =(m, 8.1 1H, Hz, H-3 1H, H-5′′); J =Hz, 6.3 and H-7′); 00 and H-700 ); 7.31 (dd, J = 6.1 and 3.2 Hz, 2H, H-50 and H-60 ); 6.68–6.62 (m, 2H, H-4000 (m, 2H, 7.60 (m, H-6 1H, H-3′′); 7.56 (t, J = 7.8 Hz, 1H, H-5′′′); 7.53–747 (m, 2H, H-6′′ and H-7′′); 7.31 (dd, J = 6.1 and 000 ); 2H, 0000 and 0000 );(s, 0000 and 3.2 andH-2); H-6′); 6.68–6.62 (m,Hz, 2H,4H, H-4′′′ H-6′′′); 2H, 3.55 (t,4H, J = 4.9 4H, H-6Hz, 3.69H-5′ (s, 2H, 3.55 (t, J = 4.9 H-3and H-53.69 2.69 (t,H-2); J = 5.0 Hz, H-2Hz, 0000 13 13 H-6 and ). C-NMR δ (ppm): 148.3, and 138.0, 136.9,13134.9, 134.7, 133.7,193.6, 133.0,159.8, 130.9,148.3, 129.9, 138.0, 129.7, H-3′′′′ H-5′′′′); 2.69 (t, J = 193.6, 5.0 Hz,159.8, 4H, H-2′′′′ H-6′′′′). C-NMR δ (ppm): 136.9, 128.1, 134.9, 127.9, 134.7,126.1, 133.7,125.3, 133.0,124.6, 130.9,123.7, 129.9,123.5, 129.7,119.3, 128.4, 128.1, 127.9, 126.1, 125.3, 123.7, 128.4, 114.0, 113.4, 107.6, 67.3, 53.7124.6, (2C) and 45.6123.5, (2C). 29H26 26S: Elemental analysis C2967.3, H26 N53.7 (510.61 calcd.: C: 68.21;analysis H: 5.13; for N: 10.97; Found: 119.3, 114.0, 113.4, for 107.6, andg/mol) 45.6 (2C). Elemental C29 N446.28. O33S (510.61 4 O3 S(2C) C: 67.89; H: 5.40; N: 11.08; S: 6.48. g/mol) calcd.: C: 68.21; H: 5.13; N: 10.97; S: 6.28. Found: C: 67.89; H: 5.40; N: 11.08; S: 6.48. 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (3j) 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (3j)

Prepared from (31 mg, mg, 0.163 0.163 mmol), Prepared from 1-(2-methoxyphenyl)-piperazine 1-(2-methoxyphenyl)-piperazine (31 mmol), potassium potassium carbonate carbonate (23 mg, mg, 0.163 0.163 mmol) mmol) and and2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone 2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) (2e) (70 (70 mg, mg, (23 give aa solid, which was purified by column chromatography silica gel using 0.163 mmol) to give on solid, which was purified by column chromatography silica gel using ◦ C; IR CH222Cl Cl222/AcOEt /AcOEt9:19:1 give of (3j) as white crystalline plates. Yield: CH toto give 6565 mgmg of (3j) as white crystalline plates. Yield: 74%;74%; m.p.:m.p.: 74–7574–75 °C; IR (KBr) − 1 1 0 −1: 1663, (KBr) cm 1372, : 1663,1172, 1372,1133, 1172,745. 1133, 745. H-NMR δ (ppm): (s, 1H,8.67 H-2(d, ); 8.67 (d, Hz, J = 8.7 1H, 11H-NMR δ (ppm): 8.99 (s, 8.99 1H, H-2′); J = 8.7 1H,Hz, H-2′′); cm−1 00 ); 8.38 (dd, J = 7.5 and 0.9 Hz, 1H, H-800 ); 8.34 (m, 1H, H-40 ); 8.07 (d, J = 8.2 Hz, 1H, H-400 ); 7.87 H-2 8.38 (dd, J = 7.5 and 0.9 Hz, 1H, H-8′′); 8.34 (m, 1H, H-4′); 8.07 (d, J = 8.2 Hz, 1H, H-4′′); 7.87 (d, J = 8.1 H-5007.80 ); 7.80 1H, H-707.66–7.60 ); 7.66–7.60(m, (m,1H, 1H,H-3′′); H-300 );7.59–7.51 7.59–7.51(m, (m,2H, 2H, H-6′′ H-600 and and H-7′′); H-700 ); J(d, = 8.1 Hz,Hz, 1H,1H, H-5′′); (m,(m, 1H, H-7′); 0 0 000 000 000 (m, 2H, 2H, H-5′ H-5 and andH-6′); H-6 );6.99–7.06 6.99–7.06(m, (m,1H, 1H,H-5′′′); H-5 ); 6.98–6.94 (m, 2H, H-3and and H-4 6.88 ); 6.88 7.33–7.27 (m, 6.98–6.94 (m, 2H, H-3′′′ H-4′′′); (d, 000 ); 3.87 (s, OCH ); 3.73 (s, 2H, H-2); 3.15 (bs, 4H, H-30000 and H-50000 ); 2.82 (bs, 4H, (d, J = 7.7 Hz, H-6 3 (s, 2H, H-2); 3.15 (bs, 4H, H-3′′′′ and H-5′′′′); 2.82 (bs, 4H, H-2′′′′ J = 7.7 Hz, H-6′′′); 3.87 (s, OCH33); 3.73 13 0000 ). 13 C-NMR δ (ppm): 193.8, 152.7, 141.5, 136.9, 134.9, 134.7, 133.8, 133.1, 130.9, 129.9, H-20000 and H-6 13 and H-6′′′′). C-NMR δ (ppm): 193.8, 152.7, 141.5, 136.9, 134.9, 134.7, 133.8, 133.1, 130.9, 129.9, 129.7, 129.7, 125.2, 124.6, 123.8, 123.6, 123.5, 121.4, 119.3, 118.8,113.4, 113.4,111.7, 111.7,67.5, 67.5, 55.8, 55.8, 128.4, 128.4, 128.2,128.2, 127.9,127.9, 126.0,126.0, 125.2, 124.6, 123.8, 123.6, 123.5, 121.4, 119.3, 118.8, 54.3(2C) and and 51.0(2C). 51.0(2C). Elemental Elemental analysis analysisfor forCC31 S (539.64 g/mol) calcd.: C: 69.00; H: 5.42; 31 2929 31 344O 54.3(2C) HH29 NN 33O S 4(539.64 g/mol) calcd.: C: 69.00; H: 5.42; N: N: 7.79; S: 5.94. Found: C: 68.81; H: 5.34; N: 7.71; S: 6.06. 7.79; S: 5.94. Found: C: 68.81; H: 5.34; N: 7.71; S: 6.06. 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanone (3k) (3k)

Prepared from 1-(2-pyrimidyl)-piperazine (96 mg, 0.583 mmol), potassium carbonate (80 mg, 0.583 mmol) and 2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) (250 mg,

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Prepared from 1-(2-pyrimidyl)-piperazine (96 mg, 0.583 mmol), potassium carbonate (80 mg, from2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone 1-(2-pyrimidyl)-piperazine (96 mg, 0.583 mmol), potassium(2e) carbonate (800.583 mg, 0.583Prepared mmol) and (250 mg, 0.583 mmol) to give a solid, which was purified by column chromatography on silica gel using 0.583 mmol) and 2-bromo-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanone (2e) (250 mg, 0.583 mmol) to give a solid, which was purified by column chromatography on silica gel using CH2Cl2/acetone ◦ C; CH /acetone 9:1 to give 136 mgcrystalline of (3k) asplates. white crystalline plates. Yield: 46% m.p.: 88–89 −1: 1664, 2to mmol) give solid, purified by column chromatography on 88–89 silica gel CH2Cl 2/acetone 9:1 2toClgive 136a mg ofwhich (3k) aswas white Yield: 46% m.p.: °C;using IR (KBr) cm −1 : 1664, 1585, 1 0 ); 8.67 (d, J =−18.7 Hz, IR (KBr) cm 1133. δ (ppm): 1H,Hz, H-2 1H-NMR 9:1 to 1360, give 136 mg1133. of (3k) as1360, white crystalline plates. 46% m.p.: °C;1H, IR H-2′′); (KBr) cm 1664, δ1168, (ppm): 8.98H-NMR (s, 1H, Yield: H-2′); 8.67 8.98 (d, J(s, =88–89 8.7 8.38: (d, J= 1585, 1168, 00 00 0 000 and 1 1H, H-2 ); 8.38 (d, J = 7.4 Hz, 1H, H-8 ); 8.34 (dd, J = 3.2, 1H, H-4 ); 8.32 (d, J = 4.8, 2H, H-4 H-NMR δ (ppm): 8.988.32 (s, 1H, J = and 8.7 Hz, 1H, 8.04 H-2′′); (d,Hz, J= 1585, 1360, 7.4 Hz, 1H,1168, H-8′′);1133. 8.34 (dd, J = 3.2, 1H, H-4′); (d, JH-2′); = 4.8,8.67 2H, (d, H-4′′′ H-6′′′); (d,8.38 J = 8.2 000 ); 8.04 (d, J = 8.2 Hz, 1H, H-400 ); 7.84 (d, J = 8.1 Hz, 1H, H-500 ); 7.79 (dd, J = 6.1 and 3.2 Hz, 1H, H-6 7.4 1H,7.84 H-8′′); (dd, J =1H, 3.2,H-5′′); 1H, H-4′); 8.32 J(d, J = 4.8, H-4′′′ and H-6′′′); J = Hz, 8.2 Hz, 1H,Hz, H-4′′); (d, 8.34 J = 8.1 Hz, 7.79 (dd, = 6.1 and 2H, 3.2 Hz, 1H, H-7′); 7.618.04 (t, J(d, = 7.6 1H, 0 ); 7.61 (t, J = 7.6 Hz, 1H, H-300 ); 7.57–7.47 (m, 2H, H-600 and H-700 ); 7.32–7.26 (m, 2H, H-50 and H-7 1H, H-4′′); 7.84 (d, = 8.1H-6′′ Hz, and 1H, H-7′′); H-5′′); 7.32–7.26 7.79 (dd, (m, J = 6.1 Hz, 1H, 6.49 H-7′); (t, JHz, = 7.6 1H, H-3′′); 7.57–7.47 (m,J 2H, 2H,and H-5′3.2 and H-6′); (t,7.61 J = 4.7 1H,Hz, H-5′′′); 0 ); 6.49 (t, J = 4.7 Hz, 1H, H-5000 ); 3.87 (t, J = 4.9 Hz, 4H, H-30000 and H-50000 ); 3.69 (s, 2H, H-2); 2.64 H-6 H-3′′); (m,4H, 2H,H-3′′′′ H-6′′ and 7.32–7.26 H-5′ and J = 4.7 Hz,and 1H,H-6′′′′). H-5′′′); 3.87 (t,7.57–7.47 J = 4.9 Hz, andH-7′′); H-5′′′′); 3.69 (s, (m, 2H,2H, H-2); 2.64 (t,H-6′); J = 4,96.49 Hz,(t,4H, H-2′′′′ 0000 and H-60000 ). 13 C-NMR δ (ppm): 193.6, 162.1, 158.1(2C), 136.9, 134.9, 134.7, (t, J =(t,4,9 4H, 13C-NMR 3.87 J =Hz, Hz,H-2 4H, H-3′′′′ and158.1(2C), H-5′′′′); 3.69 (s, 2H, H-2); 2.64133.7, (t, J =133.1, 4,9 Hz, 4H, 129.9, H-2′′′′ 129.6, and H-6′′′′). δ4.9 (ppm): 193.6, 162.1, 136.9, 134.9, 134.7, 130.9, 128.4, 13C-NMR 133.7, 133.1, 130.9, 129.9, 129.6, 128.4, 128.1, 127.9, 126.1, 125.2, 124.6, 123.7, 123.5, 119.3, 113.4, 110.5, δ (ppm): 193.6, 162.1, 158.1(2C), 136.9, 134.9, 134.7, 133.7, 133.1, 130.9, 129.9, 129.6, 128.4, 128.1, 127.9, 126.1, 125.2, 124.6, 123.7, 123.5, 119.3, 113.4, 110.5, 67.3, 53.8(2C) and 44.1(2C). Elemental 67.3, 53.8(2C) and 44.1(2C). Elemental analysis for C H N O S (511.59 g/mol) calcd.: C: 65.74; H: 4.93; 28 25 110.5, 3 67.3, 128.1, 127.9, 126.1, 125.2, 123.7, 123.5, 119.3, 53.8(2C) and 44.1(2C). analysis for C 28H25N 5O3S 124.6, (511.59 g/mol) calcd.: C: 113.4, 65.74; H:5 4.93; N: 13.69; S: 6.27. Found: C:Elemental 65.61; H: N: 13.69; S: 6.27. 65.61;g/mol) H: 5.16;calcd.: N: 13.52; S: 6.49. analysis for C28S: HFound: 25N5O3S C: (511.59 C: 65.74; H: 4.93; N: 13.69; S: 6.27. Found: C: 65.61; H: 5.16; N: 13.52; 6.49. 5.16; N: 13.52; S: 6.49. 1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone 1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone(3l) (3l) 1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone (3l)

Prepared from morpholine morpholine (35 mg, mg, 0.40 0.40 mmol), mmol), potassium potassium carbonate (46 mg, 0.33 mmol) and 2-bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone (2f) (136 (136 mg, 0.33 0.33 mmol) to give Prepared from morpholine (35 mg, 0.40 mmol), potassium (46 mg, mmol) anda 2-bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanonecarbonate (2f) gel, which was was purified purifiedby bycolumn columnchromatography chromatographyon onsilica silicagel gelusing using CH /acetone 9:1 to give 2-bromo-1-(1-(4-methoxyphenylsulfonyl)-1H-indol-3-yl)ethanone (2f) (136 mg, mmol) to give a CH 2Cl 2/acetone 9:1 to give 138 2 Cl 20.33 1 : 1665, −1:cm 138 mg of product acolumn yellow gel. Yield: m.p.: product instate; gel IR (KBr) gel, was purified by silica gel CHstate; 2Cl to−give 138 mg which of product (3l) (3l) as aas yellow gel.chromatography Yield: 81%;81%; m.p.:on product inusing gel IR2/acetone (KBr) cm9:1 1665, 1378, 1 H-NMR δ (ppm): 8.66 (s, 1H, H-20 ); 8.33 (dd, J = 6.5 and 1.3 Hz, 1H, 0 7.93 −1: 1665, 1H-NMR 1378, 573.(3l) H-4 mg of1169, product as a yellow gel. 81%;8.33 m.p.: product gel1.3 state; 1169, 573. δ (ppm): 8.66 (s,Yield: 1H, H-2′); (dd, J = 6.5 in and Hz, IR 1H,(KBr) H-4′);cm 7.93 (dd, );J1378, = 7.0 0 7.9 (d, J = 9.1 Hz, 2H, H-200 and H-600 ); 7.30–7.39 (m, 2H, H-50 and 1H-NMR (dd, J 573. = 7.0 and Hz, 1H,(d, H-7 1169, δ (ppm): 8.66 (s,Hz, 1H,2H, H-2′); 8.33 (dd, J = 6.5 and 1.3(m, Hz,2H, 1H,H-5′ H-4′); 7.93 (dd,6.92 J = 7.0 and 1.2 Hz, 1H,1.2 H-7′); 7.9 J = );9.1 H-2′′ and H-6′′); 7.30–7.39 and H-6′); (d, 0 ); 6.92 (d, J = 9.1 Hz, 2H, H-300 and H-500 ); 3.76–3.79 (m, 7H, H-30000 , H-50000 and OCH ); 3.68 (s, 2H, H-6 and 1.2Hz, Hz,2H, 1H,H-3′′ H-7′); 7.9H-5′′); (d, J = 3.76–3.79 9.1 Hz, 2H, H-6′′); 7.30–7.39 (m,3);2H, H-5′ H-6′); 6.92 (d, J = 9.1 and (m,H-2′′ 7H, and H-3′′′′, H-5′′′′ and OCH 3.68 (s, and 2H, H-2); 2.61 (bs, 3 0000 , H-60000 ). 13 C-NMR δ (ppm): 193.3, 164.8, 134.9, 133.2, 129.9 (2C), 129.2, 2.61 (bs, 4H, 13H-2 JH-2); = 9.1 Hz, 2H, H-3′′ and H-5′′); 3.76–3.79 (m, 7H, H-3′′′′, OCH 3); 3.68 (s, 128.3, 2H, H-2); 2.61 (bs, 4H, H-2′′′′, H-6′′′′). C-NMR δ (ppm): 193.3, 164.8, 134.9,H-5′′′′ 133.2,and 129.9 (2C), 129.2, 126.1, 125.2, 128.3, 126.1, 125.2, 123.4, 119.6, 115.3(2C), (2C), 113.4, 67.3 (2C), 67.1,129.9 56.2,(2C), 54.2 analysis (2C). Elemental analysis 4H, H-2′′′′, H-6′′′′). C-NMR δ (ppm): 193.3, 164.8, 134.9, 133.2, 129.2, 128.3, 126.1, 125.2, 123.4, 119.6, 115.3 13 (2C), 113.4, 67.3 67.1, 56.2, 54.2 (2C). Elemental for C 21H 22N 2O5S for C21119.6, H Ocalcd.: g/mol) calcd.: 60.85; H:54.2 5.35; N: C: 6.76; S: 7.74. Found: C: H: 123.4, (2C), 113.4, 67.3 (2C), 67.1, (2C). Elemental analysis for60.70; C217.80. H22 N25.53; O5S (414.47 g/mol) C: 60.85; H: 5.35; N:C: 6.76; S:56.2, 7.74. Found: 60.70; H: 5.53; N: 6.85; S: 22 N2115.3 5 S (414.47 N: 6.85;g/mol) S: 7.80.calcd.: C: 60.85; H: 5.35; N: 6.76; S: 7.74. Found: C: 60.70; H: 5.53; N: 6.85; S: 7.80. (414.47 1-(1-(3,5-Difluorophenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone (3m) 1-(1-(3,5-Difluorophenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone 1-(1-(3,5-Difluorophenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanone (3m) (3m)

Prepared from morpholine (37 mg, 0.42 mmol), potassium carbonate (70 mg, 0.54 mmol) and Prepared from morpholine (37 mg, 0.42 mmol), potassium carbonate carbonate mmol) and 2-bromo-1-(1-(3,5-difluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2g) (174(70 mg,mg, 0.420.54 mmol) to give 2-bromo-1-(1-(3,5-difluorophenylsulfonyl)-1H-indol-3-yl)ethanone (174 mg, give a 2-bromo-1-(1-(3,5-difluorophenylsulfonyl)-1H-indol-3-yl)ethanone (2g) (174 mg, 0.42mmol) mmol) give a gel, which was purified by column chromatography on silica gel(2g) using CH 2Cl0.42 2/acetone 9:1toto to give a gel, which was purified by column chromatography on silica gel using CH2Cl2/acetone 9:1 to give

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gel, which was purified by column chromatography on silica gel using CH2 Cl2 /acetone 9:1 to give 142 mg of product (3m) as an orange gel. Yield: 80%; m.p.: product in gel state; IR (KBr) cm−1 : 1685, 1607, 1444, 1300, 1389, 1173, 1132, 992, 614. 1 H-NMR δ (ppm): 8.63 (s, 1H, H-20 ); 8.35 (d, J = 7.4 Hz, 1H, Molecules 2016, 21, 1070 22 of 33 H-40 ); 7.92 (d, J = 7.9 Hz, 1H, H-70 ); 7.49 (bs, 2H, H-200 and H-600 ); 7.40 (m, 2H, H-50 and H-60 ); 7.06 (t, −1: 1685, 00 ); 3.78(3m) 000 ); 3.67 000 and H-6000 ). mg of product an orange m.p.: (s, product in gel state; (KBr) J = 7.7 Hz,142 1H, H-4 (bs,as4H, H-3000 gel. andYield: H-580%; 1H, H-2); 2.61 IR (bs, 4H,cm H-2 1444, 1300, 1389, 1173, 1132, 992, 614. 1H-NMR δ (ppm): 8.63 (s, 1H, H-2′); 8.35 (d, J = 7.4 Hz, 1H, 13 C-NMR 1607, δ (ppm): 193.3, 163.3 (dd, J = 256.9 and 11.7 Hz, 2C), 140.8 (t, J = 8.9 Hz, 1C), 134.8, 132.8, H-4′); 7.92 (d, J = 7.9 Hz, 1H, H-7′); 7.49 (bs, 2H, H-2′′ and H-6′′); 7.40 (m, 2H, H-5′ and H-6′); 7.06 (t, 128.4, 126.7, 123.8, 120.7, 113.3, (m,H-5′′′); 3C), 3.67 67.5, (2C),2.61 54.3 Elemental analysis for J = 125.8, 7.7 Hz, 1H, H-4′′); 3.78 (bs, 4H, 111.1 H-3′′′ and (s,67.3 1H, H-2); (bs,(2C). 4H, H-2′′′ and H-6′′′). Molecules 2016, 21, 1070 22 of 33 13 C20 H18 F2 NC-NMR calcd.: 57.14; 4.32; C: 57.27; δ (ppm):g/mol) 193.3, 163.3 (dd, JC: = 256.9 andH: 11.7 Hz, N: 2C),6.66; 140.8 S: (t, 7.63. J = 8.9Found: Hz, 1C), 134.8, 132.8,H: 4.53; N: 2 O4 S (420.43 128.4, 125.8, 123.8, 120.7, 113.3, gel. 111.1Yield: (m, 3C), 67.3 (2C), 54.3 (2C). Elemental for 6.81; S: 7.77. 142 mg126.7, of product (3m) as an orange 80%;67.5, m.p.: product in gel state; IR (KBr)analysis cm−1: 1685, C20H181444, F2N2O1300, 4S (420.43 calcd.: C:614. 57.14; H: 4.32;δN: 6.66; S: 7.63. C: 8.35 57.27; N: 6.81; 1H-NMR (ppm): 8.63 (s, Found: 1H, H-2′); (d,H:J =4.53; 7.4 Hz, 1H, 1607, 1389, g/mol) 1173, 1132, 992, S: 7.77. H-4′);Procedure 7.92 (d, J = 7.9 Hz, 1H, H-7′); 7.49 (bs, 2H, H-2′′ and H-6′′); 7.40 (m, 2H, H-5′ and H-6′); 7.06 (t, 4.3.3. General for 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanol J =(4a–m) 7.7 Hz, 1H, H-4′′); 3.78 (bs, 4H, H-3′′′ and H-5′′′); 3.67 (s, 1H, H-2); 2.61 (bs, 4H, H-2′′′ and H-6′′′). Derivatives 4.3.3. General Procedure 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanol 13 C-NMR δ (ppm): 193.3, for 163.3 (dd, J = 256.9 and 11.7 Hz, 2C), 140.8 (t, J = 8.9 Hz, 1C), 134.8, 132.8, Derivatives (4a–m) 128.4, 126.7, 125.8, 123.8, 120.7, 113.3, 111.1 (m, 3C), 67.5, 67.3 (2C), 54.3 (2C). Elemental analysis for 2-(4-(Pyridin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4a) C 20H18F2N2O4S (420.43 g/mol) calcd.: C: 57.14; H: 4.32; N: 6.66; S:(4a) 7.63. Found: C: 57.27; H: 4.53; N: 6.81; 2-(4-(Pyridin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol S: 7.77. 4.3.3. General Procedure for 2-(4-(Aryl)piperazin-1-yl)-1-(1-arylsulfonyl-1H-indol-3-yl)ethanol Derivatives (4a–m) 2-(4-(Pyridin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4a)

To a solution of (3a) (200 mg, 0.419 mmol) in ethanol (30 mL) was added sodium borohydride

To a solution of (3a) (200 mg, 0.419 mmol) in ethanol (30 mL) was added sodium borohydride (17 mg, 0.450 mmol) in one portion and mixture was vigorously stirred at room temperature until the (17 mg, 0.450 mmol) in had onedisappeared portion and mixture was vigorously at room temperature until starting material by checking TLC. Adding water (30 stirred mL) stopped the reaction. The the starting material had disappeared by checking TLC. Adding water (30 mL) stopped the reaction. organic phase was extracted with CH2Cl2 (3 × 30 mL). The combined organic layers were dried with anhydrous sodium sulfate and removal solvent under vacuum afforded a residue, which was The organic phase was extracted with CH2ofClthe 2 (3 × 30 mL). The combined organic layers were dried further purified byof column chromatography on silica gel using CH2was Cl2/acetone 9:1 to give 200 mg of To a solution (3a) (200 mg, 0.419 mmol) in ethanol (30under mL) added sodium borohydride with anhydrous sodium sulfate and removal of the solvent vacuum afforded a residue, which −1: 3422, 1595, 1438, 1369, (4a)mg, as white crystalline plates. Yield: m.p.:was 72.4–73.9 °C; IR (KBr)atcm (17 0.450 mmol) in one portion and98%; mixture vigorously stirred room temperature until the was further purified by column chromatography on gelH-3′′′′); using7.91 CH /acetone 9:1 to7.69 give 200 mg 1H-NMR 2 Cl δ (ppm): 8.13 (dd, J = 4.7 and 1.2silica Hz, 1H, (d, J =28.3 Hz, H-4′); 1174, 574. starting material had disappeared by checking TLC. Adding water (30 mL) stopped the1H, reaction. The ◦ C; −1 : 3422, of (4a) as white crystalline plates. Yield: 98%; m.p.: 72.4–73.9 IR (KBr) cm (d, J = 8.3 Hz, 2H, H-2′′ and H-6′′); 7.55 (d, J = 7.8 Hz, 1H, H-7′); 7.51 (s, 1H, H-2′); 7.45–7.38 (m, 1H, organic phase was extracted with CH2Cl2 (3 × 30 mL). The combined organic layers were dried with1595, 1438, 1 H-NMR H-5′′′′); (t, J = 7.4 1H, (m, 1H,and H-5′); (d, 1H, J afforded = 8.1 Hz,0000 and sodium sulfate andH-6′); removal of the solvent under vacuum a2H, residue, 1369, 1174,anhydrous 574. 7.23 δHz, (ppm): 8.137.19–7.14 (dd, J= 4.7 1.27.13 Hz, H-3 ); H-3′′ 7.91which (d, H-5′′); J was = 8.3 Hz, 1H, 6.61–6.53 (m, 2H, H-4′′′′ and H-6′′′′); 4.98 (dd, J = 10.1 and 3.1 Hz, 1H, H-1); 3.59–3.44 (m, 4H, H-3′′′′ 0 00 00 0 0 ); 7.45–7.38 further purified by column chromatography on silica gel using CH 2Cl2/acetone 9:1 to give 200 mg H-4 ); 7.69 (d, J = 8.3 Hz, 2H, H-2 and H-6 ); 7.55 (d, J = 7.8 Hz, 1H, H-7 ); 7.51 (s, 1H, H-2of and H-5′′′′); (m,plates. 2H, H-2a′′′′ H-6a′′′′); 2.70 (d, J =°C; 10.3 1H,cm H-2a); 2.631595, (dd, J1438, = 12.51369, and −1: 3422, (4a) as white2.82–2.75 crystalline Yield:and 98%; m.p.: 72.4–73.9 IRHz, (KBr) 0000 0 0 (m, 1H, H-5 ); 1H, 7.23 (t, J 2.55–2.48 = 7.4 Hz, H-6 ); and 7.19–7.14 (m, 1H, H-5 ); 7.13 (d, J(ppm): = 8.1 Hz, 2H, H-300 3.4 Hz, H-2b); (m,1H, 2H, H-6b′′′′); 2.25 (s, 3H, CH 3).J 13 1H-NMR δ (ppm): 8.13 (dd,H-2b′′′′ J = 4.7 and 1.2 Hz, 1H, H-3′′′′); 7.91 (d, =C-NMR 8.3 Hz, δ 1H, H-4′);159.4, 7.69 1174, 574. 0000 0000126.9 and H-500 );(d, 6.61–6.53 (m,135.5, 2H,and H-4 and ); Hz, 4.98 (dd, J= 10.1 and123.0, 3.1 120.3, Hz, 1H, H-1); 148.0, 137.6, 135.3, 129.9 (2C),H-6 128.9, (2C), 124.8, 123.2, 123.1, 113.8, 113.6, J = 145.0, 8.3 Hz, 2H, H-2′′ H-6′′); 7.55 (d, J = 7.8 1H, H-7′); 7.51 (s, 1H, H-2′); 7.45–7.38 (m, 1H, 3.59–3.44 0000 64.0, 0000 107.2, and7.19–7.14 22.7. analysis for C0000 26H28 O3SHz, (476.59 g/mol) calcd.: H-5′′′′); 7.2363.2, (t, J53.0 = 7.4 Hz,45.4 1H,(2C) H-6′); (m,0000 1H, H-5′); 7.13 (d, = 48.1 H-3′′ Hz, and H-5′′); (m, 4H, H-3 and H-5 );(2C), 2.82–2.75 (m, 2H,Elemental H-2a and H-6a );J N 2.70 (d, J2H, = 10.3 1H,C:H-2a); 2.63 65.52; H: 5.92; N: 11.76; S:and 6.73. Found: C: (dd, 65.37;J =H:10.1 5.83; N:0000 11.50; 6.79. 00003.59–3.44 13 6.61–6.53 (m,Hz, 2H, H-4′′′′ H-6′′′′); 4.98 and 3.1 Hz,S:1H, H-1); 4H,CH H-3′′′′ (dd, J = 12.5 and 3.4 1H, H-2b); 2.55–2.48 (m, 2H, H-2b and H-6b ); 2.25 (s,(m, 3H, 3 ). C-NMR and H-5′′′′); 2.82–2.75 (m, 2H, H-2a′′′′ and H-6a′′′′); 2.70 (d, J = 10.3 Hz, 1H, H-2a); 2.63 (dd, J = 12.5 and 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol δ (ppm): 159.4, 148.0, 145.0, 137.6, 135.5, 135.3, 129.9 (2C), 128.9,(4b) 126.9 (2C), 124.8, 123.2, 123.1, 123.0, 3.4 Hz, 1H, H-2b); 2.55–2.48 (m, 2H, H-2b′′′′ and H-6b′′′′); 2.25 (s, 3H, CH3). 13C-NMR δ (ppm): 159.4, 120.3, 113.8, 113.6, 107.2, 64.0, 63.2, 53.0 (2C), 45.4 (2C) and 22.7. Elemental analysis for 113.6, C26 H28 N4 O3 S 148.0, 145.0, 137.6, 135.5, 135.3, 129.9 (2C), 128.9, 126.9 (2C), 124.8, 123.2, 123.1, 123.0, 120.3, 113.8, 107.2, 64.0, 63.2, C: 53.065.52; (2C), 45.4 andN: 22.7. Elemental analysis for C26H 4O3S (476.59 g/mol) (476.59 g/mol) calcd.: H:(2C) 5.92; 11.76; S: 6.73. Found: C:28N65.37; H: 5.83; N:calcd.: 11.50;C:S: 6.79. 65.52; H: 5.92; N: 11.76; S: 6.73. Found: C: 65.37; H: 5.83; N: 11.50; S: 6.79.

2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4b) 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4b)

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Molecules 2016, 21, 1070 Molecules 2016, 21, 1070

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Prepared from (3b) (200 mg, 0.395 mmol) and sodium borohydride (17 mg, 0.450 mmol) to give a Prepared from (3b) (200 mg, 0.395 mmol) and sodium borohydride (17 mg, 0.450 mmol) to give from (3b) (200 mg, 0.395 mmol) and sodium borohydride (17 mg, 0.450 mmol) give solid,Prepared which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to to obtain a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain ◦ − 1 a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 197 mg of product (4b) as white crystalline plates. Yield: 99%; m.p.: 86.3–86.9 C; IR (KBr) cm −1 : 3446, 197 mg of product (4b) as white1 crystalline plates. Yield: 99%; m.p.: 86.3–86.90 °C; IR (KBr) cm −1: 3446, 197 mg of product (4b)748, as white crystalline plates. 8.00 Yield: m.p.: IR(d, (KBr) cm Hz, : 3446, 1371, 1174, 1241, 1121, 574. 1 H-NMR δ (ppm): (d,99%; J = 8.3 Hz,86.3–86.9 1H, H-4 ),°C; 7.80 J = 8.2 2H, 1371, 1174, 1241, 1121, 748, 574. H-NMR δ (ppm): 8.00 (d, J = 8.3 Hz, 1H, H-4′), 7.80 (d, J = 8.2 Hz, 2H, 1 00 ,1174, 1371, J =0 ),8.3 Hz, 7.80 J =0 ), 8.27.22–7.27 Hz, 2H, H-2 H-6001241, ), 7.651121, (d, J 748, = 7.8574. Hz, H-NMR 1H, H-70δ),(ppm): 7.60 (s,8.00 1H,(d, H-2 7.34 (t,1H, J = H-4′), 7.6 Hz, 1H,(d,H-6 H-2′′, H-6′′), 7.65 (d, J = 7.8 Hz,00 1H, H-7′), 7.60 (s, 1H, H-2′), 7.34 (t, J = 7.6 Hz, 1H, H-6′), 7.22–7.270000 (m, 3H, 00 Jand 0000 ),7.34 0000 and H-2′′, H-6′′), (d, = 7.8H-5 Hz, ),1H, H-7′), 7.60 1H,H-5 H-2′), (t, J = 7.6 Hz, 1H,H-3 H-6′), 7.22–7.27 3H, (m, 3H, H-507.65 , H-3 7.08–7.01 (m,(s,1H, 7.01–6.93 (m, 2H, H-4 (m, ), 6.90 H-5′, H-3′′ and H-5′′), 7.08–7.01 (m, 1H, H-5′′′′), 7.01–6.93 (m, 2H, H-3′′′′ and H-4′′′′), 6.90 (d, J = 7.9 Hz, 0000 000 H-5′, H-3′′ and H-5′′), 7.08–7.01 (m, 1H, H-5′′′′), 7.01–6.93 (m, 2H, H-3′′′′ and H-4′′′′), 6.90 (d, J = 7.9 Hz, (d, J = 7.9 Hz, 1H, H-6 ), 5.06 (dd, J = 9.6, 3.9 Hz, 1H, H-1), 3.90 (s, 3H, OCH3 ), 3.16 (bs, 4H, H-3 1H, H-6′′′′), 5.06 (dd, J = 9.6, 3.9 Hz, 1H, H-1), 3.90 (s, 3H, OCH 3), 3.16 (bs, 4H, H-3′′′ and H-5′′′), 2.99 000 ),Hz, 1H, H-6′′′′), J = 9.6, 1H, H-1), 3H,2.71 OCH 3), 3.16 (bs, 000 H-3′′′ 2.99 and H-5000 ), 5.06 2.99 (dd, (bs, 2H, H-23.9 2.85–2.75 (m,3.90 2H, (s, H-2), (bs, 2H, H-6 4H, ), 2.36 (s,and 3H,H-5′′′), CH ), 1.70 (bs, 2H, H-2′′′), 2.85–2.75 (m, 2H, H-2), 2.71 (bs, 2H, H-6′′′), 2.36 (s, 3H, CH3), 1.70 (bs, 1H,3 OH). 13 (bs, 2H, H-2′′′), 2.85–2.75 (m, 2H, H-2), 2.71 (bs, 2H, H-6′′′), 2.36 (s, 3H, CH 3), 1.70 (bs, 1H, OH). (bs, 1H, OH). C-NMR δ (ppm): 152.6, 145.4, 141.4, 135.9, 135.6, 130.3 (2C), 129.4, 127.3 (2C), 125.2, 13 δ (ppm): 152.6, 145.4, 141.4, 135.9, 135.6, 130.3 (2C), 129.4, 127.3 (2C), 125.2, 123.6, 123.5, 13C-NMR C-NMR δ (ppm):123.4, 152.6, 145.4,120.7, 141.4, 135.9,114.2, 135.6, 130.364.3, (2C), 129.4, 127.3 123.6, 123.6, 123.5, 111.6, 63.4, 55.8, 53.8,(2C), 51.2,125.2, 31.4 (2C) and123.5, 22.0. 123.5, 123.4, 123.5, 121.4, 120.7, 121.4, 118.6, 114.2, 118.6, 111.6, 64.3, 63.4, 55.8, 53.8, 51.2, 31.4 (2C) and 22.0. Elemental 123.5, 123.4, 121.4, 120.7, 118.6, 114.2, 111.6, 64.3, 63.4, 55.8, 53.8, 51.2, 31.4 (2C) and 22.0. Elemental Elemental C28 H31 N3 O4 S (505.63 g/mol) Calcd.: C: 66.51; H: 6.18; N: 8.31; S: 6.34. Found: analysis foranalysis C28H31Nfor 3O4S (505.63 g/mol) Calcd.: C: 66.51; H: 6.18; N: 8.31; S: 6.34. Found: C: 66.21; H: analysis for C28HN: 31N3O4S (505.63 g/mol) Calcd.: C: 66.51; H: 6.18; N: 8.31; S: 6.34. Found: C: 66.21; H: C: 66.21; H: 6.00; 8.09; S: 6.63. 6.00; N: 8.09; S: 6.63. 6.00; N: 8.09; S: 6.63. 2-(4-(Pyrimidin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4c) 2-(4-(Pyrimidin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4c) 2-(4-(Pyrimidin-2-yl)piperazin-1-yl)-1-(1-tosyl-1H-indol-3-yl)ethanol (4c)

Prepared from (3c) (75 mg, 0.157 mmol) and sodium borohydride (10 mg, 0.264 mmol) to give a Prepared from (3c) (75 mg, 0.157 mmol) and sodium borohydride (10 mg, 0.264 mmol) to give a solid, which was purified by column chromatography chromatography on silica silica gel using using AcOEt/hexane 9:1 to obtain solid, which was purified by column chromatographyon on silicagel gel usingAcOEt/hexane AcOEt/hexane 9:1 to obtain 51 mg of (4c) as as white white crystalline crystalline plates. plates. Yield: Yield: 68%; 68%; m.p.: m.p.: 81–82 81–82 ◦°C; IR (KBr) (KBr) cm cm−−11: 3423, C; IR 3423, 1586, 1586, 1360, 1360, 51 mg of (4c) as white crystalline plates. Yield: 68%; m.p.: 81–82 °C; IR (KBr) cm−1:: 3423, 1586, 1360, 1 000 000 0 ); 7.77 H-NMR δ (ppm): 8.32 (d, J = 4.6 Hz, 2H, H-4 H-4′′′ and H-6′′′); 7.98 (d, JJ ==8.3 Hz, 1H, H-4′); 1174, 574. H-6 ); 7.98 (d, 8.3 Hz, 1H, H-4 7.77 1 1174, 574. H-NMR δ (ppm): 8.32 (d, J = 4.6 Hz, 2H, H-4′′′ and H-6′′′); 7.98 (d, J = 8.3 Hz, 1H, H-4′); 7.77 00 ); 7.62 0 ); 7.58 0 ); 7.31 (d, J = 8.0 Hz, 2H, H-2 H-2′′00 and H-6′′); (d, JJ == 7.8 Hz, 1H, H-7′); (s, 1H, H-2′); (t, JJ == 7.7 Hz, and H-6 7.62 (d, 7.8 Hz, 1H, H-7 7.58 (s, 1H, H-2 7.31 (t, 7.7 Hz, (d, J = 8.0 Hz, 2H, H-2′′ and H-6′′); 7.62 (d, J = 7.8 Hz, 1H, H-7′); 7.58 (s, 1H, H-2′); 7.31 (t, J = 7.7 Hz, 0 ); 7.27–7.18 (m, 3H, H-5 0 , H-3 00 and H-5 00 ); 6.51 (t, J = 4.6 Hz, 1H, H-5 000 ); 5.1 1H, H-6 H-6′); H-5′, H-3′′ H-5′′); H-5′′′); (dd, J = 10.2 and 5.1 (dd, J = 1H, H-6′); 7.27–7.18 (m, 3H, H-5′, H-3′′ and H-5′′); 6.51 (t, J = 4.6 Hz, 1H, H-5′′′); 5.1 = 10.2 and 0000 00002.75–2.86 0000 , H-6a 0000 H-2a); 2.8 Hz, 1H, H-1); 3.82–3.95 (m, 4H, H-3′′′′ and H-5′′′′); (m,(m, 3H,3H, H-2a′′′′, H-6a′′′′ and 2.70 Hz, 1H, H-1); 3.82–3.95 (m, 4H, H-3 and H-5 ); 2.75–2.86 H-2a and H-2a); 2.8 Hz, 1H, H-1); 3.82–3.95 (m, 4H, H-3′′′′ and H-5′′′′); 2.75–2.86 (m, 3H, H-2a′′′′, H-6a′′′′ and H-2a); 2.70 13C-NMR 0000 0000 (dd, J = 12.5 and 3.0 Hz, 1H, H-2b); 2.50–2.59 (m, 2H, H-2b′′′′ and H-6b′′′′); 2.34 (s, 3H, CH 3 ). 2.70 (dd, J = 12.5 and 3.0 Hz, 1H, H-2b); 2.50–2.59 (m, 2H, H-2b and H-6b ); 2.34 (s, 3H, CH 13 3 ). (dd, J = 12.5 and 3.0 Hz, 1H, H-2b); 2.50–2.59 (m, 2H, H-2b′′′′ and H-6b′′′′); 2.34 (s, 3H, CH3). C-NMR 13 C-NMR δ (ppm): 162.0, 158.2 (2C),158.2 145.4, 135.9, 135.7, 130.3 (2C), 129.4, 127.3 (2C), 125.2, 123.5 (2C), 123.4, δ (ppm): 162.0, (2C), 145.4, 135.9, 135.7, 130.3 (2C), 129.4, 127.3 (2C), 125.2, 123.5 (2C), δ (ppm): 162.0, 158.2 (2C), 145.4, 135.9, 135.7, 130.3 (2C), 129.4, 127.3 (2C), 125.2, 123.5 (2C), 123.4, 120.7, 120.7, 114.2, 110.5, 110.5, 64.5, 63.6, 22.0. analysis for C25for H27N25 5O 123.4, 64.5,53.5 63.6,(2C), 53.544.2 (2C),(2C) 44.2and (2C) andElemental 22.0. Elemental analysis H33SS N5 O3 S 27(477.58 120.7, 114.2, 114.2, 110.5, 64.5, 63.6, 53.5 (2C), 44.2 (2C) and 22.0. Elemental analysis for C25H27C N5O (477.58 g/mol) calcd.: C: 62.87; H: 5.70; N: 14.66; S: 6.71. Found: C: 62.67; H: 5.93; N: 14.82; S: 6.76. (477.58 g/mol)C:calcd.: S: 6.71. C: Found: H: 14.82; 5.93; N: g/mol) calcd.: 62.87;C: H:62.87; 5.70; H: N: 5.70; 14.66;N: S:14.66; 6.71. Found: 62.67;C: H:62.67; 5.93; N: S: 14.82; 6.76. S: 6.76. 1-(1-(4-Chlorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4d) (4d) 1-(1-(4-Chlorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol 1-(1-(4-Chlorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4d)

Prepared from (3d) (170 mg, 0.343 mmol) and sodium borohydride (16 mg, 0.422 mmol) to give Prepared from (3d) (170 mg, 0.343 mmol) and sodium borohydride (16 mg, 0.422 mmol) to give a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to yield a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to yield

Molecules 2016, 21, 1070

25 of 35

Prepared from (3d) (170 mg, 0.343 mmol) and sodium borohydride (16 mg, 0.422 mmol) to give a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 Molecules 2016, 21, 1070 24 of 33 to yield 126 mg of compound (4d) as pale brown crystalline plates. Yield: 75%; m.p.: 81–82 ◦ C; Molecules 2016, 21, 10701586, 1360, 1176, 570. 1 H-NMR δ (ppm): 8.32 (d, J = 4.7 Hz, 2H, H-4000 and of 33 −1 IR (KBr) cm− 3423, H-6 126 mg of1 :compound (4d) as pale brown crystalline plates. Yield: 75%; m.p.: 81–82 °C; IR (KBr)24cm : 000 ); 0 ); 17.81 00 and 00 ); 7.62 0 ); 7.56 H-NMR 8.32 (d,H-2 J = 4.7 Hz, 2H, and(d, H-6′′′); 7.96Hz, (d, 1H, J = 8.3 Hz, 3423, 1360,1H, 1176, 570. 7.96 (d, J =1586, 8.3 Hz, H-4 (d, Jδ=(ppm): 8.6 Hz, 2H, H-6H-4′′′ J = 7.8 H-7 126 mg0 of compound (4d) as pale brown crystalline00 plates. Yield: 75%; m.p.: 81–82 °C; IR (KBr) cm−1: 00 0 1H, H-4′); 7.81 (d, J = 8.6 Hz, 2H, H-2′′ and H-6′′); 7.62 (d, J = 7.8 Hz, 1H, H-7′); 7.56 (s, 1H, H-2′); 7.39 (s, 1H, H-2 ); 7.39 (d, J = 8.6 Hz, 2H, H-3 and H-5 ); 7.33 (t, J = 7.7, 1H, H-6 ); 7.25 (t, J = 7.5 Hz, 1H, 3423, 1586, 1360, 1176, 570. 1H-NMR δ (ppm): 8.32 (d, J = 4.7 Hz, 2H, H-4′′′ and H-6′′′); 7.96 (d, J = 8.3 Hz, 000 7.33 0000 (d, J = 8.6 2H,Hz, H-3′′ andH-5 H-5′′); J = 7.7, H-6′); 7.25Hz, (t, J 1H, = 7.5H-1); Hz, 1H, H-5′); 6.51 (t, J = 4.7 Hz, H-50 );1H, 6.51 (t, JHz, = 4.7 5.08(t, (dd, J = 1H, 10.0 and 3.83-3.92 H-3 H-4′); 7.81 (d, J = 1H, 8.6 Hz, 2H,);H-2′′ and H-6′′); 7.62 (d,3.2 J = 7.8 Hz, 1H, H-7′); 7.56 (s, (m, 1H, 4H, H-2′); 7.39 and 1H, H-5′′′); 5.08 (dd, J = 10.0 and 3.2 Hz, 1H, H-1); 3.83-3.92 (m, 4H, H-3′′′′ and H-5′′′′); 3.37 (bs, 1H, 0000 and H-6a0000 ); 2.77 (d, J = 10.3 Hz, 1H, H-2a); 2.72 H-50000 OH);and 2.79–2.87 (m,(t,2H, H-2a (d,);J3.37 = 8.6(bs, Hz, 1H, 2H, H-3′′ H-5′′); 7.33 J = 7.7, 1H, H-6′); 7.25 (t, J = 7.5 Hz, 1H, H-5′); 6.51 (t, J = 4.7 Hz, OH); 2.79–2.87 (m, 2H, H-2a′′′′ and H-6a′′′′); 2.77 (d, J = 10.30000 Hz, 1H, H-2a); (dd, J = 12.5 and 3.4 00002.72 (dd, J1H, = 12.5 and5.08 3.4(dd, Hz,J1H, H-2b); 2.52–2.61 2H, H-2b and ). 13H-5′′′′); C-NMR δ (ppm): H-5′′′); = 10.0 and 3.2 Hz, 1H,(m, H-1); 3.83-3.92 (m, 4H,H-6b H-3′′′′ and 3.37 (bs, 1H,162.0, 13 Hz, 1H, H-2b); 2.52–2.61 (m, 2H, H-2b′′′′ and H-6b′′′′). C-NMR δ (ppm): 162.0, 158.2 (2C), 141.0, 136.9, 2.79–2.87 (m, 2H, H-2a′′′′ and H-6a′′′′); 2.77 (d, J(2C), = 10.3125.5, Hz, 1H, H-2a); 2.72123.2, (dd, J 120.9, = 12.5 and 3.4110.6, 158.2OH); (2C), 141.0, 136.9, 135.8, 130.1 (2C), 129.4, 128.6 124.3, 123.9, 114.1, 135.8, 130.1 (2C), 129.4, 128.6 (2C), 125.5, 124.3, 123.9, 123.2, 120.9, 114.1, 110.6, 64.5, 63.5, 53.5 (2C), 13C-NMR δ (ppm): 162.0, 158.2 (2C), 141.0, 136.9, Hz, 1H, H-2b); 2.52–2.61 (m, 2H, H-2b′′′′ and H-6b′′′′). 64.5, 44.1 63.5,(2C). 53.5Elemental (2C), 44.1analysis (2C). Elemental analysis for C24g/mol) H24 ClN (498.00 calcd.: 5 O3 SC: for C24H24ClN 5O3S (498.00 calcd.: 57.88; g/mol) H: 4.86; N: 14.06;C:S:57.88; 135.8, 130.1 (2C), 129.4, 128.6 (2C), 125.5,H: 124.3, 123.9, 123.2,S:120.9, 114.1, 110.6, 64.5, 63.5, 53.5 (2C), H: 4.86; N: 14.06; S: 6.44. Found: C: 57.97; 4.88; N: 13.69; 6.78. 6.44. Found: C: 57.97; H: 4.88; N: 13.69; S: 6.78. 44.1 (2C). Elemental analysis for C24H24ClN5O3S (498.00 g/mol) calcd.: C: 57.88; H: 4.86; N: 14.06; S:

1-(1-(4-Fluorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4e)(4e) 1-(1-(4-Fluorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol 6.44. Found: C: 57.97; H: 4.88; N: 13.69; S: 6.78. 3'''

H H4''' 1-(1-(4-Fluorophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4e)

H5b'''' H6a''''

N H3''' H5a''''

H4'''H5''' N

NN H3b'''' H5a'''' H6b'''' N H5b'''' 3a'''' H OH N N H H1 H6a'''' H5' 2b''''3b'''' H H 2a'''' 6b'''' H H H2b H3a'''' OH2a N H4' H1 H H6'5' H H2b'''' 2a'''' H2' H 2b N H H7' H2a H6' O S O 2' H N H2'' H6'' H7' O S O

H5'''

4'

2'' H H3''

6'' H H5''

F H3''

H5''

F and sodium borohydride (13 mg, 0.340 mmol) to give a Prepared fromfrom (3e)(3e) (140 mg, 0.292 mmol) Prepared (140 mg, 0.292 mmol) and sodium borohydride (13 mg, 0.340 mmol) to give solid, which was purified by column chromatographyon on silica silica gel 9:1 to obtain solid,awhich was purified by column chromatography gelusing usingAcOEt/hexane AcOEt/hexane 9:1 to obtain Prepared from (3e) (140 mg, 0.292 mmol) and sodium borohydride (13 mg, 0.340◦mmol) to give 97 mg of compound (4e) as pale yellow crystalline plates. Yield: 69%; m.p.: 72–73 °C; IR (KBr) cm : −1 : 97 mg of compound (4e) as pale yellowchromatography crystalline plates. Yield: 69%; m.p.: 72–73 C; IR (KBr)−1cm a solid, which was purified by column on silica gel using AcOEt/hexane 9:1 to obtain 1H-NMR δ (ppm): 8.32 (d, J = 4.7 Hz, 2H, H-4′′′ and000 1 000 H-6′′′); 7.97 (d, 3422, 1587, 1360, 1180, 982, 573. 3422,971587, 1180, 982, 573. δ (ppm):plates. 8.32 Yield: (d, J =69%; 4.7 m.p.: Hz, 2H, H-4 H-6 mg of1360, compound (4e) as pale H-NMR yellow crystalline 72–73 °C; IRand (KBr) cm−1);: 7.97 J = 8.3 Hz, 1H, H-4′); 7.90 (dd, J = 8.9 and 4.9, 2H, H-2′′ and H-6′′); 7.63 (d, J = 7.8 Hz, 1H, H-7′); 7.57 (s, 0 00 00 0 1 (d, J =3422, 8.3 Hz, H-4 ); 7.90 8.9 andδ4.9, 2H,8.32 H-2(d,and ); 7.63 (d, J =and 7.8 H-6′′′); Hz, 1H, H-7 H-NMR (ppm): J = H-6 4.7 Hz, 2H, H-4′′′ 7.97 (d,); 7.57 1587,1H, 1360, 1180, 982,(dd, 573.J = 1H, H-2′); 7.19–7.35 (m, 2H, H-5′ and H-6′); 7.09 (t, J = 8.5 Hz, 2H, H-3′′ and H-5′′); 6.50 (t, J = 4.7 Hz, 0 0 0 00 00 (s, 1H, ); 7.19–7.35 2H, H-5 and H-6 7.09H-2′′ (t, J and = 8.5H-6′′); Hz, 2H, H-51H, ); 6.50 J =(s, 4.7 Hz, J =H-2 8.3 Hz, 1H, H-4′);(m, 7.90 (dd, J = 8.9 and 4.9,); 2H, 7.63H-3 (d, J =and 7.8 Hz, H-7′);(t,7.57 1H, H-5′′′); 5.07 (dd, J = 10.2 and 3.3 Hz, 1H, H-1); 3.84–3.95 (m, 4H, H-3′′′′0000 and H-5′′′′); 0000 3.46 (bs, 1H, 1H,000 H-2′); 7.19–7.35 2H,and H-5′3.3 and H-6′); (t, 3.84–3.95 J = 8.5 Hz, (m, 2H, 4H, H-3′′H-3 and H-5′′); 4.7 Hz, 1H, H-5 ); 5.07 (dd, J =(m, 10.2 Hz, 1H,7.09 H-1); and6.50 H-5(t, J);=3.46 (bs, 1H, OH); 2.77–2.86 (m, 2H, H-2a′′′′ and H-6a′′′′); 2.77 (d, J = 10.2 Hz, 1H, H-2a); 2.71 (dd, J = 12.6 and 3.5 0000and H-5′′′); 5.07 (dd, = 10.2 3.3H-6a Hz, 0000 1H,);H-1); (m, Hz, 4H, H-3′′′′ and H-5′′′′); 3.46 (bs, 1H, and OH);1H, 2.77–2.86 (m,2.52–2.59 2H, JH-2a and 2.77 3.84–3.95 (d, 13JC-NMR = 10.2 1H, 166.1 H-2a); (dd, J = 1C); 12.6 Hz, 1H, H-2b); (m, 2H, H-2b′′′′ and H-6b′′′′). δ (ppm): (d,2.71 J = 257.2 Hz, 0000 0000 13 OH); 2.77–2.86 (m, 2H, H-2a′′′′ and H-6a′′′′); 2.77 (d, J = 10.2 Hz, 1H, H-2a); 2.71 (dd, J = 12.6 and 3.5 Hz, 3.5 Hz, 1H,158.2 H-2b); 2.52–2.59 (m, (d, 2H,J =H-2b δ (ppm): 166.1 123.8; (d, J =123.3; 257.2 162.0; (2C); 135.8; 134.6 3.1 Hz, and 1C); H-6b 130.1 (d,).J = C-NMR 9.7 Hz, 2C); 125.4; 124.2; Hz, 1H, H-2b); 2.52–2.59 (m, 2H, H-2b′′′′ and H-6b′′′′). 13C-NMR δ (ppm): 166.1 (d, J = 257.2 Hz, 1C); 1C); 162.0; 158.2 (d, (2C); 134.6 J = 114.1; 3.1 Hz, 1C);64.5; 130.1 (d,53.5 J = 9.7 2C); 125.4; 124.2;analysis 123.8; 123.3; 120.8; 117.1 J = 135.8; 22.9 Hz, 2C); (d, 115.2; 110.5; 63.6; (2C);Hz, 44.2 (2C). Elemental 162.0; 158.2 (2C); 135.8; 134.6 (d, J = 3.1 Hz, 1C); 130.1 (d, J = 9.7 Hz, 2C); 125.4; 124.2; 123.8; 123.3; C24H(d, 24FN 3S (481.54 g/mol) calcd.: C: 59.86; H: 64.5; 5.02; N: 14.54; S: (2C); 6.66. Found: C: 59.82; H: 5.13;analysis N: 120.8;for 117.1 J 5=O22.9 Hz, 2C); 115.2; 114.1; 110.5; 63.6; 53.5 44.2 (2C). Elemental 120.8; 117.1 (d, J = 22.9 Hz, 2C); 115.2; 114.1; 110.5; 64.5; 63.6; 53.5 (2C); 44.2 (2C). Elemental analysis 14.29; S: 6.99. for Cfor H FN O S (481.54 g/mol) calcd.: C: 59.86; H: 5.02; N: 14.54; S: 6.66. Found: C: 59.82; H: 5.13; 24 C24 5 3 24H24FN5O3S (481.54 g/mol) calcd.: C: 59.86; H: 5.02; N: 14.54; S: 6.66. Found: C: 59.82; H: 5.13; N: N: 14.29; S:S:6.99. 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol (4f) 14.29; 6.99.

1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol (4f)(4f)

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Prepared from (3f) (130 mg, 0.222 mmol) and sodium borohydride (10 mg, 0.269 mmol) to33give a Molecules 2016, 21, 1070 25 of solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain Prepared from 0.222crystalline mmol) andplates. sodium borohydride (10 mg, 0.269 ◦mmol) to give 2016, 21, 1070 25 of 33cm−1 : 72 mgMolecules of compound (4f)(3f) as (130 palemg, brown Yield: 56%; m.p.: 157–158 C; IR (KBr) a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 000 1 3382, 1592, 1384, 1174, 1122, 1098, 607, 568. H-NMR δ (ppm): 8.20 (dd, J = 4.8 and 1.2 Hz, 1H, −1 H-3 ); 72 mg of compound (4f) (130 as pale crystalline 56%; °C; mmol) IR (KBr) : Prepared from (3f) mg,brown 0.222 mmol) andplates. sodium borohydride (10157–158 mg, 0.269 tocm give 00 Yield: 00 );m.p.: 0 ); 7.96 (d, J = 8.3 Hz, 1H, H-40 ); 7.76 (d, J = 8.6 Hz, 2H, H-2 and H-6 7.62 (d, J = 7.8 Hz, 1H, H-7 7.57 1592, 1384, 1122,by 1098, 607,chromatography 568. 1H-NMR δ (ppm): 8.20 (dd, J =AcOEt/hexane 4.8 and 1.2 Hz,9:1 1H, H-3′′′); a3382, solid, which was1174, purified column on silica gel using to obtain 00 00 0 000 (d, J =7.96 8.7(d, Hz, H-31H,and H-5 7.55 ); 7.45–7.53 (m, 1H,(d, H-5 ); Hz, 7.331H, (t, JH-7′); = 7.37.57 Hz, 1H, =2H, 8.3 Hz, H-4′); 7.76);brown (d, J =(s, 8.61H, Hz, H-2 2H,plates. H-2′′ and H-6′′); J = 7.8 72 mg ofJ compound (4f) as pale crystalline Yield: 56%;7.62 m.p.: 157–158 °C; IR (KBr) cm−1: 0 ); 6.62–6.68 (m, 2H, H-4000 and H-6000 ), 5.06 (dd, J = 9.6 and 3.7 Hz, 1H, H-50 );3382, 7.25 (t, J = 7.2 Hz, 1H, H-6 1H-NMR (d, J =1592, 8.7 Hz, 2H,1174, H-3′′1122, and 1098, H-5′′);607, 7.55568. (s, 1H, H-2′);δ7.45–7.53 (m,(dd, 1H, JH-5′′′); 7.331.2 (t, Hz, J = 7.3 1H, 1384, (ppm): 8.20 = 4.8 and 1H,Hz, H-3′′′); 0000 and H-50000 ); 2.81–2.91 (m, 2H, H-2a0000 and H-6a0000 ); 2.69–2.80 (m, 2H, H-1);7.96 3.52–3.66 (m, H-3 H-5′); J Hz, = 4H, 7.21H, Hz, 1H, H-6′); 6.62–6.68 (m,2H, 2H,H-2′′ H-4′′′and andH-6′′); H-6′′′),7.62 5.06(d,(dd, = 9.6 Hz, 7.57 1H, (d,7.25 J = (t, 8.3 H-4′); 7.76 (d, J = 8.6 Hz, J = J7.8 Hz,and 1H,3.7 H-7′); 0000 and 0000 ).2H, 13 C-NMR H-1); 3.52–3.66 (m,H-3′′ 4H, and H-3′′′′ and H-5′′′′); 2.81–2.91 H-2a′′′′ and H-6a′′′′); 2.69–2.80 (m, 2H, (2C); H-2a(d, and (m, H-5′′); 2H, H-2b H-6b(m, δH-5′′′); (ppm): 159.8; 139.0 J =H-2b); 8.7 Hz,2.56–2.63 2H, 7.55 (s, 1H, H-2′); 7.45–7.53 (m, 1H, 7.33 (t, J =148.4; 7.3 Hz, 1H, 13 H-2a and H-2b); 2.56–2.63 2H,6.62–6.68 H-2b′′′′ and H-6b′′′′). C-NMR δ 5.06 (ppm): 139.0 (2C); 138.1;H-5′); 138.0; 135.8; (2C); 125.5; 124.4; 123.9; 123.2; 120.9; 114.1; 107.6; 102.2; 7.25 (t, J = 129.4; 7.2 Hz,128.4 1H,(m, H-6′); (m, 2H, H-4′′′ and H-6′′′), (dd,159.8; J 114.0; = 9.6148.4; and 3.7 Hz, 1H, 64.4; 138.1; 138.0;45.8 135.8; 129.4; 128.4 (2C); 125.5; 124.4; 123.2; 120.9; 114.1; 114.0; 107.6; 102.2; 3.52–3.66 (m, 4H, H-3′′′′ andanalysis H-5′′′′); 2.81–2.91 (m, and H-6a′′′′); 2.69–2.80 (m,63.6; 2H, 63.6; H-1); 53.4 (2C); (2C). Elemental for C123.9; IN2H, S (588.46 g/mol) calcd.: C: 64.4; 51.03; H: 4.28; 25 H25 4 O3H-2a′′′′ 13 53.4 (2C); 45.8 (2C). Elemental analysis for C 25 H 25 IN 4 O 3 S (588.46 g/mol) calcd.: C: 51.03; H: 4.28; N: H-2a 2.56–2.63 (m,H: 2H,4.44; H-2b′′′′ and H-6b′′′′). N: 9.52; S: and 5.45.H-2b); Found: C: 50.85; N: 9.43; S: 5.51. C-NMR δ (ppm): 159.8; 148.4; 139.0 (2C); 9.52; S:138.0; 5.45. 135.8; Found: C: 50.85; 4.44; N: 9.43; S: 123.9; 5.51. 123.2; 120.9; 114.1; 114.0; 107.6; 102.2; 64.4; 63.6; 138.1; 129.4; 128.4H: (2C); 125.5; 124.4;

1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanol (4g) 53.4 (2C); 45.8 (2C). Elemental analysis for C25H25IN4O3S (588.46 g/mol) calcd.: C: 51.03; H: 4.28; N: 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanol (4g) 9.52; S: 5.45. Found: C: 50.85; H: 4.44; N: 9.43; S: 5.51. 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanol (4g)

Prepared mg, 0.224 mmol)and andsodium sodium borohydride borohydride (10 mmol) to give Prepared fromfrom (3g)(3g) (138(138 mg, 0.224 mmol) (10mg, mg,0.269 0.269 mmol) to give a a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain −1: 86 mg of compound (4g) (138 as pale brown crystalline plates. Yield: 62%; m.p.: °C;◦mmol) IR (KBr) Prepared from 0.224crystalline mmol) andplates. sodium borohydride (10109–110 mg, 0.269 tocm give 86 mg of compound (4g)(3g) as palemg, brown Yield: 62%; m.p.: 109–110 C; IR (KBr) cm−1 : 1H-NMR δ (ppm): 7.96 (d, J = 8.2 Hz, 1H, 1500, 1447, 1175,by1241, 1120, 748, 734, 608, 568. a3423, solid, which was1385, purified column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 1 3423,H-4′); 1500, 1447, 1385, 1175, 1241, 1120, 748, 734, 608, 568.Hz, H-NMR δ (ppm): 7.96 (d, J= 8.2H-2′, Hz, 1H, −1: (d, J = 8.4 Hz, H-2′′brown and H-6′′); 7.63 (d, J = 7.8Yield: 1H, H-7′); (d, J =°C; 8.3IR Hz, 3H, cm 86 mg 7.75 of compound (4g)2H, as pale crystalline plates. 62%; m.p.:7.56 (KBr) 00 and H-6 00 ); 7.63 (d, 0 );109–110 0, H-40 );H-3′′ 7.75and (d, H-5′′); J = 8.47.33 Hz,(t,2H, H-2 J = 7.8 Hz, 1H, H-7 7.56 (d, J = 8.3 Hz, 3H, H-2 1H-NMR = 7.7 Hz, 1H, H-6′); 7.25734, (t, J 608, = 7.4568. Hz, 1H, H-5′); δ6.98-7.06 (ppm): (m, 7.961H, (d,H-5′′′); J = 8.26.90–6.97 Hz, 1H, 3423, 1500, 1447, 1385,J1175, 1241, 1120, 748, 00 ); 7.33 (t, J = 7.7 Hz, 1H, H-60 ); 7.25 (t, J = 7.4 Hz, 1H, H-50 ); 6.98-7.06 (m, 1H, H-5000 ); H-300H-4′); and H-5 (m, 2H, H-3′′′ H-4′′′); 6.87H-2′′ (d, Jand = 7.9H-6′′); Hz, 1H, H-6′′′); (t, J =1H, 6.7H-7′); Hz, 1H, 3H,3H, OCH 3); 7.75 (d, and J = 8.4 Hz, 2H, 7.63 (d, J =5.05 7.8 Hz, 7.56H-1); (d, J3.87 = 8.3(s,Hz, H-2′, 000 and H-4000 ); 6.87 (d, J = 7.9 Hz, 1H, H-6000 ); 5.05 (t, J = 6.7 Hz, 1H, H-1); 3.87 6.90–6.97 (m, 2H, H-3 3.14 (bs, 4H, H-3′′′′ and H-5′′′′); 2.97 (bs, 2H, H-2a′′′′ and H-6a′′′′); 2.77 (d, J = 6.5 Hz, 2H, H-2); 2.70 (bs, H-3′′ and H-5′′); 7.33 (t, J = 7.7 Hz, 1H, H-6′); 7.25 (t, J = 7.4 Hz, 1H, H-5′); 6.98-7.06 (m, 1H, H-5′′′); 6.90–6.97 0000 δ (ppm): 0000 ); 2.97 0000 and 0000 ); 2H, H-2b′′′′ and H-6b′′′′). C-NMR 141.5; 139.0 138.1; 135.8; 129.5; 128.4 (2C); (s, 3H, OCH (bs, 4H,136.87 H-3 (bs, 2H, H-6a 2.77 (d,OCH J125.5; = 36.5 (m, 2H, H-3′′′ and H-4′′′); (d, Jand = 7.9H-5 Hz, 152.7; 1H, H-6′′′); 5.05 (t,(2C); JH-2a = 6.7 Hz, 1H, H-1); 3.87 (s, 3H, ); Hz, 3 ); 3.14 0000 0000 13 124.6; 123.9; 123.6; 123.2; 121.5; 120.9; 118.7; 114.1; 111.7; 102.2; 64.4; 63.5; 55.8 (2C); 53.8; 51.1 (2C). 3.14 (bs, 4H, H-3′′′′ H-5′′′′); 2.97H-6b (bs, 2H,).H-2a′′′′ and H-6a′′′′); 2.77 (d, J =141.5; 6.5 Hz, 2H, H-2); (bs,135.8; 2H, H-2); 2.70 (bs, 2H,and H-2b and C-NMR δ (ppm): 152.7; 139.0 (2C);2.70 138.1; Elemental analysis for C13 27C-NMR H123.9; 28IN3Oδ 4S(ppm): (617.50 g/mol) calcd.: C:(2C); 52.52; H:114.1; 4.57; N: 6.80; 102.2; S: 5.19(2C); Found: C: 55.8 H-2b′′′′ and H-6b′′′′). 152.7; 141.5; 139.0 138.1; 135.8; 129.5; 128.4 125.5; 129.5;2H, 128.4 (2C); 125.5; 124.6; 123.6; 123.2; 121.5; 120.9; 118.7; 111.7; 64.4; 63.5; 52.40; H: 4.75; N: 6.65; S: 5.55. 123.6;Elemental 123.2; 121.5; 120.9; 118.7; 111.7; 102.2; 64.4; 63.5; 55.8 (2C); 53.8; 51.1 (2C). (2C); 124.6; 53.8; 123.9; 51.1 (2C). analysis for C114.1; 27 H28 IN3 O4 S (617.50 g/mol) calcd.: C: 52.52; H: 4.57; Elemental analysis for C 27H28IN3O4S (617.50 g/mol) calcd.: C: 52.52; H: 4.57; N: 6.80; S: 5.19 Found: C: 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4h) N: 6.80; S: 5.19 Found: C: 52.40; H: 4.75; N: 6.65; S: 5.55. 52.40; H: 4.75; N: 6.65; S: 5.55.

1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4h) 1-(1-(4-Iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4h)

Molecules 2016, 21, 1070

27 of 35

Molecules 2016, 21, 1070 26 of 33 Prepared from (3h) (147 mg, 0.25 mmol) and sodium borohydride (12 mg, 0.3 mmol) to give a solid,Molecules which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 yield 2016, 21, from 1070 (3h) (147 mg, 0.25 mmol) and sodium borohydride (12 mg, 0.3 mmol) to 26 ofto 33 Prepared give a ◦ − 1 98 mg of (4h) as was brown crystalline plates. Yield: 67%; on m.p.: 171–172 IR (KBr) cm9:1 :to3451, solid, which purified by column chromatography silica gel usingC; AcOEt/hexane yield 1585, 1 H-NMR 000 Prepared from (3h) (147 mg, 0.25 mmol) and sodium borohydride (12 mg, 0.3 mmol) to give a 000 ); −1 1485, 98 1449, 1359, 1174, 1125, 982, 609, 569. δ (ppm): 8.31 (d, J = 4.8 Hz, 2H, H-4 and H-6 mg of (4h) as brown crystalline plates. Yield: 67%; m.p.: 171–172 °C; IR (KBr) cm : 3451, 1585, 1485, 0 ); 7.74 00 and 0 ); 7.56 solid, which was purified by column chromatography silica using 9:1 toH-7 yield 7.96 (d, J =1359, 8.3 Hz, 1H, H-4982, (d, J =1H-NMR 8.6 Hz, δ2H, H-2on ); 7.62 (d, JH-4′′′ = 7.8and Hz,H-6′′′); 1H, 1449, 1174, 1125, 609, 569. (ppm): 8.31 (d,H-6 Jgel = 004.8 Hz, AcOEt/hexane 2H, 7.96 −1: 3451, 1585, 1485, 98 mg of (4h) as brown crystalline plates. Yield: 67%; m.p.: 171–172 °C; IR (KBr) cm 00 00 0 0 8.3 2H, Hz, 1H, = 8.6(s,Hz, 2H, H-2′′ and (t, H-6′′); 7.62Hz, (d, 1H, J = 7.8 Hz, (d, J =(d, 8.5J =Hz, H-3 H-4′); and 7.74 H-5(d,); J7.55 1H, H-2 ); 7.32 J = 7.4 H-6 ); 1H, 7.24H-7′); (t, J =7.56 7.3 (d, Hz, 1H, 1H-NMR δ (ppm): 8.31 (d, J = 4.8 Hz, 2H, H-4′′′ and H-6′′′); 7.96 1449, 1174, 1125, 982, 569. (s, 000609, 0000 and 8.51359, Hz,J 2H, H-3′′ H-5′′); 7.55 7.32 (t, = 7.41H, Hz, H-1); 1H, H-6′); 7.24 (t,(m, J = 7.3 1H, H-50 );J =6.50 (t, = 4.7, 1H,and H-5 ); 5.06 (dd,1H, J =H-2′); 10.0 and 3.3J Hz, 3.82–3.94 4H,Hz, H-3 (d, J = 8.3 Hz, 1H, H-4′); 7.74 (d, J = 8.6 Hz, 2H, H-2′′ and H-6′′); 7.62 (d, J = 7.8 Hz, 1H, H-7′); 7.56 (d, 0000 5.06 H-5′); 6.50 (t, J (m, = 4.7, 1H,H-2a H-5′′′); (dd, J 0000 = 10.0 and(d, 3.3J Hz, 1H,Hz, H-1); 3.82–3.94 (m, 4H, H-3′′′′ H-50000 ); 2.76–2.84 2H, and(s, H-6a ); 2.75 = 10.1 1H, H-2a); 2.70 (dd, J = and 12.6 and JH-5′′′′); = 8.5 Hz, 2H, H-3′′ 1H, H-2′); (t, J = 7.4 H-6′); 7.24 (t, JJ == 12.6 7.3 Hz, 2.76–2.84 (m,and 2H, H-5′′); H-2a′′′′7.55 and H-6a′′′′); 2.757.32 (d, J0000 = 10.1 Hz,Hz, 1H,1H, H-2a); 2.70 (dd, and1H, 3.7 0000 13 3.7 Hz, 1H, H-2b); 2.51–2.57 (m, 2H, H-2b and H-6b ). C-NMR δ (ppm): 162.0; 158.2 (2C); H-5′); 6.50 (t, J =2.51–2.57 4.7, 1H, (m, H-5′′′); (dd,and J = H-6b′′′′). 10.0 and 133.3 Hz, 1H, H-1); 3.82–3.94 (m,(2C); 4H, 139.0 H-3′′′′(2C); and139.0 Hz, 1H, H-2b); 2H, 5.06 H-2b′′′′ C-NMR δ (ppm): 162.0; 158.2 (2C); H-5′′′′); 138.1; 135.8; 129.4; 2H, 128.4 (2C);and 125.5; 124.4; 123.9; 120.9; 114.1; 110.5; 102.2; 64.5; 63.6; 2.76–2.84 H-2a′′′′ H-6a′′′′); 2.75 (d, J 123.2; =120.9; 10.1 Hz, 1H,110.5; H-2a); 2.70 64.5; (dd, J63.6; = 12.6 and 3.7 53.5 138.1; 135.8; 129.4;(m, 128.4 (2C); 125.5; 124.4; 123.9; 123.2; 114.1; 102.2; 53.5 (2C); 13 (2C); 44.2 44.21H, (2C).Elemental Elemental analysis for C24 H g/mol) calcd.: 48.90; H:139.0 4.10;(2C); N: 11.88; Hz, 2.51–2.57 (m, 2H, H-2b′′′′ and H-6b′′′′). C-NMR δ (ppm): 162.0;C: 158.2 (2C); 24 IN 5 O3 S (589.45 (2C).H-2b); analysis for C 24H24IN5O3S (589.45 g/mol) calcd.: C: 48.90; H: 4.10; N: 11.88; S: 5.44. 138.1; 135.8; 129.4; 128.4 (2C); 125.5; 124.4; 123.9; 123.2; 120.9; 114.1; 110.5; 102.2; 64.5; 63.6; 53.5 (2C); S: 5.44. Found: C: 48.71; H: 4.28; N: 11.67; S: 5.58. Found: C: 48.71; H: 4.28; N: 11.67; S: 5.58.

44.2 (2C). Elemental analysis for C24H24IN5O3S (589.45 g/mol) calcd.: C: 48.90; H: 4.10; N: 11.88; S: 5.44.

1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol (4i)(4i) Found: C: 48.71; H: 4.28; N: 11.67; S: 5.58. H3'''

4'''

H 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyridin-2-yl)piperazin-1-yl)ethanol (4i) N H3''' H5a'''' H5b'''' NN H6a''''

H5' HH6'5' H7' H6' H8'' H7''

5'''

H6''' 5''' H H3b'''' H5a'''' H6b'''' 5b'''' H 3a'''' OH N H H4' N 6''' H1 H6a'''' 2b'''' H 2a'''' H H3b'''' H6b'''' H 2b H OH H3a'''' H4' H2a N H1 2b'''' H2' H2a'''' H N H2b H2a O S O H2' N H2''

H7' H8'' O

S

O

7'' H6''

2'' H3''

H

H H6''

H4'''H

5''

H

4''

H3''

4'' H5'' Hand Prepared fromfrom (3i)(3i) (110(110 mg, 0.216 mmol) (10mg, mg,0.269 0.269 mmol) to give a Prepared mg, 0.216 mmol) andsodium sodium borohydride borohydride (10 mmol) to give solid, which was purified by column chromatographyon on silica silica gel 9:1 to obtain solid,awhich was purified by column chromatography gelusing usingAcOEt/hexane AcOEt/hexane 9:1 to obtain Prepared from (3i) (110 mg, brown 0.216 mmol) and sodium borohydridem.p.: (10 mg, 0.269 mmol) tocm give −1: 80of mg of compound as pale crystalline plates. Yield: 80–81°C; 80 mg compound (4i)(4i) as pale brown crystalline plates. Yield:72%; 72%; m.p.: 80–81◦IR C; (KBr) IR (KBr) cm−1 : a3423, solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 1H-NMR δ (ppm): 8.72 (d, J = 8.6 Hz, 1H, H-2′′); 8.20 1 00 1594, 1437, 1361, 1171, 1122, 981, 769, 600. 3423,80 1594, of 1437, 1361, 1171, 1122, 981, 769,crystalline 600. H-NMR δYield: (ppm): 8.72 (d, 80–81°C; J = 8.6 Hz, 1H, H-2 −1); 8.20 compound (4i) 8.10 as pale plates. 72%; IR (d, mg J = 3.8 Hz, 1H, H-3′′′); (d, Jbrown = 7.4 Hz, 1H, H-4′′); 8.02 (d, J = 8.2 Hz,m.p.: 1H, H-4′); 7.85 (d,(KBr) J = 9.3cm Hz,: 000 00 0 (d, J =3423, 3.8 Hz, 1H, H-31361, ); 8.10 (d, J = 981, 7.4 Hz, H-4 ); 8.02 (ppm): (d, J = 8.2 Hz, J1H, H-4 ); 7.85H-2′′); (d, J = 9.3 Hz, 1H-NMR 8.72 8.6 Hz, 8.20 1594, 1437, 1171, 769,1H, 600. 1H,0 H-7′); 7.83 (d, J = 9.1 Hz,1122, 1H, H-8′′); (s, 1H, H-2′);δ07.60–7.65 (m,(d, 2H,=H-3′′ and1H, 7.53 00 ); 7.78 00H-5′′); 00(t, 1H, H-7 );= 3.8 7.83Hz, (d,1H, J =H-3′′′); 9.1 Hz, 1H, H-8 7.78 (s, 1H, 8.02 H-2(d, ); 7.60–7.65 (m, H-4′); 2H, H-3 and H-5Hz, ); 7.53 (d, J 8.10 (d, J = 7.4 Hz, 1H, H-4′′); J = 8.2 Hz, 1H, 7.85 (d, J = 9.3 J = 7.6 Hz, 1H, H-6′); 7.44–7.50 (m, 2H, H-5′ and H-5′′′); 7.16–7.27 (m, 2H, H-6′′ and H-7′′); 6.61–6.67 0 ); 7.44–7.50 (m, 2H, H-50 and H-5000 ); 7.16–7.27 (m, 2H, H-600 and H-700 ); 6.61–6.67 (t, J =(m, 7.62H, Hz,H-4′′′ 1H, 1H, H-7′); 7.83H-6 (d, J = 9.1 Hz, 1H, H-8′′); 7.78 (s, 1H, H-2′); 7.60–7.65 (m, 2H, H-3′′ and H-5′′); 7.53 (t, and H-6′′′); 5.08 (dd, J = 10.1 and 3.0 Hz, 1H, H-1); 3.51–3.64 (m, 4H, H-3′′′′ and H-5′′′′); 000 and 000 ); 00006.61–6.67 J = H-4 7.6 Hz, 1H,2H, H-6′); 7.44–7.50 (m, H-5′ and 7.16–7.27 (m, 2H, H-7′′); (m, 2H, H-6 5.08 (dd, J =2H, 10.1 and 3.0 Hz, H-1); 3.51–3.64 (m,and H-3and and H-50000 ); 2.80–2.88 (m, H-2a′′′′ and H-6a′′′′); 2.77 (d, J =H-5′′′); 10.3 1H, Hz, 1H, H-2a); 2.69H-6′′ (dd, J4H, = 12.5 3.4 Hz, 0000 0000 (m, 2H, H-4′′′ H-6′′′); 5.08H-6a (dd, =);10.1 3.0 1H, H-1); 3.51–3.64 (m, 4H, H-3′′′′ and H-5′′′′); 13C-NMR 2.80–2.88 (m, 2H, and H-2a 2.77and (d, J =Hz, 10.3 Hz, 1H, H-2a); 2.69 (dd, J = 12.5 and 3.4 Hz, H-2b); 2.55–2.63 (m, 2H,and H-2b′′′′ andJ H-6b′′′′). δ (ppm): 159.8; 148.4; 137.9; 135.9; 135.8; 134.7; 2.80–2.88 (m, 2H, H-2a′′′′ and 2.77 (d, J = 10.3 Hz, 1H, H-2a); 2.69 (dd, J = 12.5 and 3.4 Hz, 0000H-6a′′′′); 0000 13 H-2b); 2.55–2.63 (m, 2H, H-2b and H-6b ). C-NMR δ (ppm): 159.8; 148.4; 137.9; 135.9; 134.5; 129.6; 129.5; 129.2; 129.0; 128.6; 127.6; 125.2; 124.5; 124.4; 123.9; 123.5; 122.9; 120.8; 114.0; 113.9;135.8; H-2b); 2.55–2.63 (m, 2H, H-2b′′′′ and H-6b′′′′). 13analysis C-NMRfor δ (ppm): 148.4; 137.9; 135.9; 135.8; 134.7; 64.5; 63.7;129.5; 53.4 (2C); 45.8129.0; (2C).Elemental C29H28159.8; N 4O3S (512.62 67.95;114.0; 134.7;107.6; 134.5; 129.6; 129.2; 128.6; 127.6; 125.2; 124.5; 124.4; 123.9;g/mol) 123.5; calcd.: 122.9;C: 120.8; 134.5; 129.6; 129.5; 129.2; 129.0; 128.6; 127.6; 125.2; 124.5; 124.4; 123.9; 123.5; 122.9; 120.8; 114.0; 113.9; 5.51; 64.5; N: 10.93; S: 53.4 6.26 Found: C: 68.10; H: 5.73; N: 11.16; S: 6.02. 113.9;H: 107.6; 63.7; (2C); 45.8 (2C).Elemental analysis for C29 H28 N4 O3 S (512.62 g/mol) calcd.: 107.6; 64.5; 63.7; 53.4 (2C); 45.8 (2C).Elemental analysis for C29H28N4O3S (512.62 g/mol) calcd.: C: 67.95; C: 67.95; H: 5.51; N: 10.93; 6.26 Found: H:11.16; 5.73; S: N:6.02. 11.16; S: 6.02. 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanol (4j) H: 5.51; N: 10.93; S: 6.26S: Found: C: 68.10;C: H:68.10; 5.73; N:

2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanol 2-(4-(2-Methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanol (4j) (4j)

Molecules 2016, 21, 1070

28 of 35

Molecules 2016, 21, 1070 of 33 Prepared from (3j) (82 mg, 0.15 mmol) and sodium borohydride (7 mg, 0.19 mmol)27to give a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain Prepared give a Molecules 2016, 21, from 1070 (3j) (82 mg, 0.15 mmol) and sodium borohydride (7 mg, 0.19 mmol) to 27 of 33 80 mg of compound (4j) as light brown crystalline plates. Yield: 61%; m.p.: 89–90 ◦ C; IR (KBr) cm−1 : solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 00 ); 8.08 3423, 1500, 1448, 1361, 1241, 1121,mmol) 747. 1and H-NMR δ (ppm): 8.73 (7 (d,mg, J =0.19 8.6 Hz, 1H, −1a: Prepared from 1172, (3j) (82 mg, 0.15 sodium borohydride mmol) toH-2 give 80 mg of compound (4j) as light brown crystalline plates. Yield: 61%; m.p.: 89–90 °C; IR (KBr) cm 00 ); 8.04 (d, J = 8.2 Hz, 1H, H-40 ); 7.87 (d, J = 8.1 Hz, 1H, H-70 ); 7.83 (d, J = 8.2 Hz, (d, J =solid, 7.4 Hz, 1H, H-4 1 which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain 3423, 1500, 1448, 1361, 1172, 1241, 1121, 747. H-NMR δ (ppm): 8.73 (d, J = 8.6 Hz, 1H, H-2′′); 8.08 (d, 00 ); 7.78 (s, 1H, H-20 ); 7.61–7.67 (m, 2H, H-300 and H-500 ); 7.55 (t, J = 7.5 Hz, 1H, H-60−1); 7.49 1H, H-8 80 of compound brown crystalline plates. 61%; m.p.: 89–90 J = mg 7.4 Hz, 1H, H-4′′); (4j) 8.04as (d,light J = 8.2 Hz, 1H, H-4′); 7.87 (d, J Yield: = 8.1 Hz, 1H, H-7′); 7.83 °C; (d, JIR= (KBr) 8.2 Hz,cm 1H,: 0 ); 7.18–7.28 00 00(ppm): 000 );H-2′′); 1H-NMR 1500, 1448, 1361, 1172, 1241, 1121, 747. δ 8.73 (d, J = 8.6 Hz, 1H, 8.08 (t, J =3423, 7.9 Hz, 1H, H-5 (m, 2H, H-6 and H-7 ); 7.00–7.06 (m, 1H, H-5 6.92–6.96 (m, H-8′′); 7.78 (s, 1H, H-2′); 7.61–7.67 (m, 2H, H-3′′ and H-5′′); 7.55 (t, J = 7.5 1H, H-6′); 7.49 (d, (t, 2H, 000 000 000 J = 7.4 Hz, 1H, H-4′′); 8.04 (d, J = 8.2 Hz, 1H, H-4′); 7.87 (d, J = 8.1 Hz, 1H, H-7′); 7.83 (d, J = 8.2 Hz, 1H, H-3 and ); 6.88 J = 7.9 (m, Hz,2H, 1H,H-6′′ H-6and ); H-7′′); 5.1 (dd, J = 9.7(m, and1H, 3.2H-5′′′); Hz, 1H, H-1); (m, 3.872H, (s, 3H, = 7.9 H-4 Hz, 1H, H-5′);(d, 7.18–7.28 7.00–7.06 6.92–6.96 0000J and 0000 00007.55 0000 7.78 (s,4H, 1H, H-2′); 7.61–7.67 (m, 2H, andJH-2a H-5′′); J =1H, 7.5 Hz, 1H, (s, H-6′); 7.49 H-3′′′ and H-4′′′); 6.88 (d, = 7.9 H-5 Hz, 1H, 5.1 (dd, = 9.7 and 3.2(t, Hz, H-1); 3.87 3H, OCH 3);H-2a, OCHH-8′′); (bs, H-3 );H-6′′′); 2.98H-3′′ (bs, 2H, and H-6a ); 2.71–2.85 (m, 4H,(t, 3 ); 3.15 = 7.9 Hz, 1H, H-5′); 7.18–7.28 (m, (bs, 2H, H-6′′ and H-7′′); 7.00–7.06 (m, 1H, H-5′′′); 6.92–6.96 2H,129.1; 0000 0000 13 C-NMR (bs, 4H, H-3′′′′ and H-5′′′′); 2.98 2H, H-2a′′′′ and141.5; H-6a′′′′); 2.71–2.85 (m, 4H, 134.5; H-2a, H-2b, H-2b′′′′ H-2b,J3.15 H-2b and H-6b ). δ (ppm): 152.7; 135.9; 135.8; 134.7; 129.5(m, (2C); 13 H-3′′′ and H-4′′′); 6.88 (d, J = 7.9 Hz, 1H, H-6′′′); 5.1 (dd, J = 9.7 and 3.2 Hz, 1H, H-1); 3.87 (s, 3H, OCH 3); H-6b′′′′). C-NMR δ (ppm): 135.9; 135.8; 134.7; 134.5; 129.5118.7; (2C); 114.0; 129.1; 129.0; 129.0;and 128.6; 127.6; 125.1 (2C); 124.5;152.7; 123.9;141.5; 123.6; 123.5; 123.0; 121.5; 120.8; 111.7;128.6; 64.4; 63.5; 3.15 (bs, 4H, H-3′′′′ and H-5′′′′); 2.98 (bs, 2H, H-2a′′′′ and H-6a′′′′); 2.71–2.85 (m, 4H, H-2a, H-2b, H-2b′′′′ 127.6; 125.1 (2C); 124.5; 123.9; 123.6; 123.5; 123.0; 121.5; 120.8; 118.7; 114.0; 111.7; 64.4; 63.5; 55.8 (2C); 55.8 (2C); 53.8; 51.1 (2C). Elemental analysis for C31 H31 N3 O4 S (541.66 g/mol) calcd.: C: 68.74; H: 5.77; 13C-NMR δ (ppm): 152.7; 141.5; 135.9; and 135.8; 134.7; 134.5; 129.5 (2C); 129.1; 129.0; 128.6; 53.8;H-6b′′′′). 51.1 (2C). Elemental analysis for C31H31N3O4S (541.66 g/mol) calcd.: C: 68.74; H: 5.77; N: 7.76; S: N: 7.76; S: 5.92 Found: C: 68.58; 5.92; N: 7.62; 5.72. 120.8; 118.7; 114.0; 111.7; 64.4; 63.5; 55.8 (2C); 127.6; 125.1 (2C); 124.5; 123.9; H: 123.6; 123.5; 123.0;S:121.5;

5.92 Found: C: 68.58; H: 5.92; N: 7.62; S: 5.72.

53.8; 51.1 (2C). Elemental analysis for C31H31N3O4S (541.66 g/mol) calcd.: C: 68.74; H: 5.77; N: 7.76; S: 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol 1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4k)(4k) 5.92 Found: C: 68.58; H: 5.92; N: 7.62; S: 5.72.

1-(1-(Naphthalen-1-ylsulfonyl)-1H-indol-3-yl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethanol (4k)

Prepared from mg, 0,143mmol) mmol)and and sodium sodium borohydride (10(10 mg, 0.260.26 mmol) to give a Prepared from (3k)(3k) (73(73 mg, 0,143 borohydride mg, mmol) to give a solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain solid, which was purified by column chromatography on silica gel using AcOEt/hexane 9:1 to obtain Prepared from (3k) (73 0,143 mmol) and sodium (10 mg, 0.26°C; mmol) to give of compound as mg, pale brown crystalline plates. borohydride Yield: 82–83 cm−1acm : −1 : ◦IR 45 mg45ofmg compound (4k)(4k) as pale brown crystalline plates. Yield:62%; 62%;m.p.: m.p.: 82–83 C; (KBr) IR (KBr) solid, which1447, was purified by 1122, column chromatography silica 8.72 gel using 9:1 to8.31 obtain (ppm): (d, J =AcOEt/hexane 8.7 Hz, 1H, H-2′′); (d, 3424, 1586, 1360, 1171, 983, 599. 11H-NMR δon 00 ); 8.31 3424,45 1586, of 1447, 1360, 1171, 1122, 983, 599. H-NMR δ (ppm): 8.72m.p.: (d, J82–83 = 8.7°C; Hz, 1H, H-2 −1: (4k) pale 8.09 brown Yield: 62%; (KBr) cm(d, J = mg 4.7 Hz,compound 2H, H-4′′′ and as H-6′′′); (d,crystalline J = 7.4 Hz,plates. 1H, H-4′′); 8.02 (d, J = 8.2 Hz, 1H, IR H-4′); 7.85 000 000 00 0 (d, J =3424, 4.7 Hz, 2H, H-4 and H-6 ); 8.09 (d, J = 7.4 Hz, 1H, H-4 ); 8.02 (d, J = 8.2 Hz, 1H, H-4 1 H-NMR (ppm): 8.72H-2′); (d, J =7.60–7.65 8.7 Hz, 1H, 8.31and (d,); 7.85 1360, 7.82 1171,(d, 1122, 983,Hz, 599.1H, J = 8.21586, Hz, 1447, 1H, H-7′); J = 8.4 H-8′′); δ7.78 (s, 1H, (m, H-2′′); 2H, H-3′′ 0 00 0 00 (d, J =JH-5′′); 7.82 (d, J =8.09 8.4 Hz, ); 7.78 (s,7.17–7.27 1H, (d, H-2J(m, 7.60–7.65 (m, 2H, H-3 =8.2 4.7Hz, Hz,1H, 2H, and H-6′′′); Hz, 1H, H-4′′); 8.02 =);8.2 Hz, 1H,and H-4′); 7.85 (d, and 7.54 (t, J H-7 =H-4′′′ 7.5);Hz, 1H, H-6′); 7.47(d, (t,JJ=1H, = 7.4 7.9H-8 H-5′); 2H, H-6′′ H-7′′), 6.50 0 7.47 (t, J = 7.9 Hz, 1H, H-50 ); 7.17–7.27 (m, 2H, H-600 and H-700 ), 6.50 H-500 ); =1H, 7.51H, Hz,H-5′′′), 1H, J(t,=7.54 Hz,J Hz, H-7′); 7.82H-6 (d, 8.4 JHz, 1H, H-8′′); 1H,H-1); H-2′);3.83–3.93 7.60–7.65(m, (m,4H, 2H,H-3′′′′ H-3′′ and J8.2 = (t, 4.7 5.09J); =(dd, = 10.2 and 2.87.78 Hz,(s,1H, 000 0000 7.54 (t,(m, JH-5 =3H, 7.5 Hz, 1H,(dd, H-6′); (t,H-2a); J = 7.9 Hz, 1H, (m, H-1, 2H, and H-7′′), (t, J =H-5′′); 4.7 Hz, 1H, ), 5.09 J =7.47 10.2 and 2.8 Hz, 1H, 3.83–3.93 (m, H-6′′ 4H, H-3 and6.50 H-50000 ); H-5′′′′); 2.75 H-2a′′′′, H-6a′′′′ and 2.69 (dd, JH-5′); = H-1); 12.57.17–7.27 and 3.1 Hz, H-2b); 2.51–2.58 (m, 0000 0000 and 13C-NMR (t, = 4.7 Hz, 1H, H-5′′′), 5.09δ H-2a); (dd, J =162.0; 10.2(dd, and J2.8 Hz, 1H, 135.8; H-1); 3.83–3.93 (m, 4H, H-3′′′′129.1; and 2H,J 3H, H-2b′′′′, H-6b′′′′). (ppm): 158.1 (2C), 135.9; 134.7; 134.5; 129.6; 129.5; 2.75 (m, H-2a , H-6a 2.69 = 12.5 and 3.1 Hz, H-1, H-2b); 2.51–2.58 (m, 2H, 0000 0000 13 H-5′′′′); 2.75 (m, 3H, H-2a′′′′, H-6a′′′′ and H-2a); 2.69 (dd, J = 12.5 and 3.1 Hz, H-1, H-2b); 2.51–2.58 (m, 129.0; 128.6; 127.6; 125.2; 124.5; 124.4; 123.9; 123.5; 122.8; 120.8; 114.0; 110.5; 64.6; 63.6; 53.5 (2C); 44.2 H-2b , H-6b ). C-NMR δ (ppm): 162.0; 158.1 (2C), 135.9; 135.8; 134.7; 134.5; 129.6; 129.5; 129.1; 13C-NMR δ (ppm): 162.0; 158.1 (2C), 135.9; 135.8; 134.7; 134.5; 129.6; 129.5; 129.1; H-2b′′′′, H-6b′′′′). (2C). Elemental analysis for 124.4; C28H27N 5O3S (513.61 g/mol) calcd.: C: 65.48; H: 5.30; N: 13.64; S: 6.24 129.0;2H, 128.6; 127.6; 125.2; 124.5; 123.9; 123.5; 122.8; 120.8; 114.0; 110.5; 64.6; 63.6; 53.5 (2C); 44.2 129.0; 128.6; 127.6; 125.2; 124.5; 124.4; 123.9; 123.5; 122.8; 120.8; 114.0; 110.5; 64.6; 63.6; 53.5 (2C); 44.2 Found: C: 65.57; H: 5.11; N: 13.49; S: 6.03. (2C). Elemental analysis for C28 H27 N5 O3 S (513.61 g/mol) calcd.: C: 65.48; H: 5.30; N: 13.64; S: 6.24 (2C). Elemental analysis for C28H27N5O3S (513.61 g/mol) calcd.: C: 65.48; H: 5.30; N: 13.64; S: 6.24 1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanol (4l) Found: C: 65.57; H: 5.11; N: 13.49; S: 6.03. Found: C: 65.57; H: 5.11; N: 13.49; S: 6.03.

1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanol (4l) 1-(1-(4-Methoxyphenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanol (4l)

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Prepared 0.18 mmol) and sodium borohydride (67 mg, 1.77 mmol) to give solid, Preparedfrom from(3l) (3l)(73 (73mg, mg, 0.18 mmol) and sodium borohydride (67 mg, 1.77 mmol) toagive a which was purified by column chromatography on silica gel using AcOEt to yield 39 mg of compound solid, which was purified by column chromatography on silica gel using AcOEt to yield 39 mg of ◦ C; IR (KBr) cm−1 : 3454, 1595, (4l) as yellow Yield:plates. 53%; m.p.: 1364, 1595, 1270, compound (4l)crystalline as yellowplates. crystalline Yield:149–152 53%; m.p.: 149–152 °C; IR (KBr) cm−1: 3454, 1 0 ); 7.81 (d, J = 9.0 Hz, 2H, H-200 and H-600 ); 1 1166, 1117, 573. H-NMR δ (ppm): 7.97 (d, J = 8.3 Hz, 1H, H-4 1364, 1270, 1166, 1117, 573. H-NMR δ (ppm): 7.97 (d, J = 8.3 Hz, 1H, H-4′); 7.81 (d, J = 9.0 Hz, 2H, 0 ); 7.31 (t, J = 7.5 Hz, 1H, H-60 ); 7.22 (t, J = 7.5 Hz, 1H, H-50 ); 7.60 J =H-6′′); 7.8 Hz,7.60 1H,(d, H-7J 0 =); 7.8 7.57Hz, (s, 1H, H-2′′(d, and 1H,H-2 H-7′); 7.57 (s, 1H, H-2′); 7.31 (t, J = 7.5 Hz, 1H, H-6′); 7.22 (t, 00 00 0000 6.85 (d,Hz, J = 9.0 2H,6.85 H-3 (d, and ); 5.02 J =and 9.1 and 4.4 5.02 Hz, 1H, 3.69–3.80 J = 7.5 1H,Hz, H-5′); J =H-5 9.0 Hz, 2H,(dd, H-3′′ H-5′′); (dd,H-1); J = 9.1 and 4.4(m, Hz,7H, 1H,H-3 H-1);, 0000 0000 0000 0000 H-5 and(m, OCH 2.68–2.77 (m, 4H, , H-2a 2.45–2.51 (m,H-2a 2H, H-2b and 3 ); H-3′′′′, 3.69–3.80 7H, H-5′′′′ andH-2a OCH3,);H-6a 2.68–2.77 (m,and 4H,H-2b); H-2a′′′′, H-6a′′′′, and H-2b); 0000 13 13C-NMR H-6b ). (m, C-NMR δ (ppm): 164.2, 135.8, 130.1,δ129.5 (2C), 129.3, 125.2, 123.5, (2C), 120.6, 114.9 2.45–2.51 2H, H-2b′′′′ and H-6b′′′′). (ppm): 164.2, 135.8, 130.1, 129.5123.4 (2C), 129.3, 125.2, 123.5, (2C), 114.2, 67.4 (2C), 64.9, 63.4, 56.1 (2C), 54.0. Elemental analysis for C H N O S (416.49 g/mol) 21 24 2 5 123.4 (2C), 120.6, 114.9 (2C), 114.2, 67.4 (2C), 64.9, 63.4, 56.1 (2C), 54.0. Elemental analysis for C21H24N2O5S calcd.: 60.56; H: 5.81; N: 6.73; 7.70 60.42; H: C: 5.88; N: 6.79; S: 7.57. (416.49 C: g/mol) calcd.: C: 60.56; H: S: 5.81; N:Found: 6.73; S: C: 7.70 Found: 60.42; H: 5.88; N: 6.79; S: 7.57. 1-(1-(3,5-Difluorophenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanol 1-(1-(3,5-Difluorophenylsulfonyl)-1H-indol-3-yl)-2-morpholinoethanol(4m) (4m)

Prepared borohydride (10(10 mg, 0.26 mmol) to give an Prepared from from(3m) (3m)(70 (70mg, mg,0.167 0.167mmol) mmol)and andsodium sodium borohydride mg, 0.26 mmol) to give oil, which waswas purified by column chromatography on silica gel using AcOEt to obtain 46 mg (4m) an oil, which purified by column chromatography on silica gel using AcOEt to obtain 46ofmg of −1 :−13381 (OH), 1606, 1444, 1384 and as a yellow oil. Yield: 66%;66%; m.p.: product is an IR IR (KBr) cmcm (4m) as a yellow oil. Yield: m.p.: product is oil; an oil; (KBr) : 3381 (OH), 1606, 1444, 1384 0 ); 7.63 (d, J = 7.8 Hz, 1H, H-70 ); 1179, 617. 11H-NMR H-NMRδδ(ppm): (ppm):7.96 7.96(d,(d, = 8.3 H-47.63 J =J 8.3 Hz,Hz, 1H,1H, H-4′); (d, J = 7.8 Hz, 1H, H-7′); 7.52 1179, 1298, 1115, 617. 0 00 00 0 ); 7.27 (m, 1H, H-50 ); 6.98 7.52 J =Hz, 0.6 Hz, H-2 ); 7.41 H-67.36 ); 7.36 H-67.27 (d, J (d, = 0.6 1H, 1H, H-2′); 7.41 (m, (m, 2H, 2H, H-2′′H-2 andand H-6′′); (m, (m, 1H, 1H, H-6′); (m, 1H, H-5′); 6.98 (tt, 00 0000 and (tt, J = 8.4 and 2.3 Hz, 1H, H-4 ); 5.03 (ddd, J = 8.6, 5.1 and 0.7 Hz, 1H, H-1); 3.77 (m, 4H, J = 8.4 and 2.3 Hz, 1H, H-4′′); 5.03 (ddd, J = 8.6, 5.1 and 0.7 Hz, 1H, H-1); 4H, H-3 H-3′′′′ 0000 ); 2.76 (m, H-5 H-2a0000 and andH-6a′′′′); H-6a0000 );2.71 2.71(s, (s,1H, 1H,H-2a); H-2a);2.70 2.70(d, (d,J= J=3.9 3.9Hz, Hz,1H, 1H,H-2b); H-2b); 2.50 2.50 (m, (m, 2H, H-5′′′′); 2.76 (m, 2H, H-2a′′′′ 0000 0000 13 H-2b and H-6b′′′′). H-6b ).13C-NMR C-NMRδδ(ppm): (ppm):163.1 163.1(dd, (dd,JJ==255.8 255.8and and11.7 11.7Hz, Hz,2C); 2C); 141.4 141.4 (t, (t, J == 8.5 8.5 Hz, Hz, 1C), H-2b′′′′ and 135.8, 135.8, 129.4, 125.8, 124.9, 124.2, 123.0, 121.0, 114.1, 111.0 (m, 2C), 110.0 (t, J = 25.0 Hz, 1C), 67.4 (2C), 64.8, 63.3, 54.0 (2C). Elemental analysis for for C20 H2020FF S (422.45 g/mol) calcd.: C: 56.86; H: 4.77; 2N 2O S4(422.45 g/mol) calcd.: C: 56.86; H: 4.77; N: 20H 2N 2 4O N: 6.63; S: 7.59 Found: C: 56.69; 4.93; 6.74; S: 7.52. 6.63; S: 7.59 Found: C: 56.69; H: H: 4.93; N: N: 6.74; S: 7.52. 1 H-NMR pK Determination Studies 4.4. 4.4. 1H-NMR pKaa Determination Studies

All on aa Bruker Bruker Avance Avance III III HD-400 HD-400 MHz MHz spectrometer spectrometer at at 298 298 K. K. All NMR NMR spectra spectra were were performed performed on 11 H-NMR experiments were acquired using water suppression in order to suppress the residual The The H-NMR experiments were acquired using water suppression in order to suppress the residual HDO Solutions of of the the 3b 3b and O were were prepared 200 µM HDO signal. signal. Solutions and 4g 4g 22 mM mM in in D D22O prepared adding adding acetone acetone 200 μM as as an an internal standard [56]. The titrations were carried out progressively in a single NMR sample for each internal standard [56]. The titrations were carried out progressively in a single NMR sample for each compound. ThepH pHwas wasadjusted adjusted with mol/L of NaOH 0.1 mol/L HCl, to the cover pH compound. The with 0.10.1 mol/L of NaOH and and 0.1 mol/L HCl, to cover pHthe ranges ranges 4.65–9.11 and 5.58–9.46 for 3b 4g solutions, respectively. pH ranges were chosen 4.65–9.11 and 5.58–9.46 for 3b and 4g and solutions, respectively. The pHThe ranges were chosen near tonear pKa to pK predicted by software MarvinSketch 16.5.2.0 from ChemAxon package [57,58]. The chemical a predicted by software MarvinSketch 16.5.2.0 from ChemAxon package [57,58]. The chemical shifts shifts (δ of ppm) the piperazine methylene protons plotted against thefor pHboth for both compounds. (δ ppm) the of piperazine methylene protons were were plotted against the pH compounds. The The pK were obtained from the inflection point of the resulting sigmoidal curve, for each compound. a pKa were obtained from the inflection point of the resulting sigmoidal curve, for each compound. 1 H chemical shift dependence on the pH for the compounds 3b and 4g, Figure Figure 77 shows shows the the 1H chemical shift dependence on the pH for the compounds 3b and 4g, respectively. Figure 7A,C shows an expansion of spectra, in the area offor interest, 3b and 4g respectively. Figure 7A,C shows an expansion of spectra, in the area of interest, 3b and for 4g compounds compounds at different pH. The signal to upfield of the doublet of methylene protons of the piperazine at different pH. The signal to upfield of the doublet of methylene protons of the piperazine ring was D correspond to inflection point in the resulting D ring was used to plot δ ppm vs. pH. In this case, the pK a used to plot δ ppm vs. pH. In this case, the pKa correspond to inflection point in the resulting sigmoidal sigmoidal from plot ppm pH,compound for each compound (Figure 7B,D). The pKa obtained curve fromcurve the plot δ the ppm vs.δpH, forvs. each (Figure 7B,D). The pKa obtained were 5.72were and

6.69 for compound 3b and 4g, respectively. The pKa value determined in D2O was corrected for H2O using the Krezel et al. equation [59].

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5.72 and 6.69 for compound 3b and 4g, respectively. The pKa value determined in D2 O was corrected for H2 O2016, using Molecules 21, the 1070Krezel et al. equation [59]. 29 of 33

Figure 7. 11H chemical shift dependence on the pH for compound 3b (A,B) and compound 4g (C,D). Figure 7. H chemical shift dependence on the pH for compound 3b (A,B) and compound 4g (C,D). The biggest doublet corresponds to the four protons in the methylenes in the α-position to nitrogen The biggest doublet corresponds to the four protons in the methylenes in the α-position to nitrogen in the piperazine. The pKaDD (pKa2) values are obtained from the inflection point of the resulting in the piperazine. The pKa (pKa2 ) values are obtained from the inflection point of the resulting sigmoidal curve. sigmoidal curve.

The chemical shift is affected by the chemical and, consequently, the magnetic environment. The chemical shift is affected the chemical consequently, magnetic environment. Therefore, the protonation of basicby species such as and, the nitrogen atomsthe in piperazine ring induce Therefore, the protonation of basic species such as the nitrogen atoms in piperazine ring induce important changes in the chemical environment in the adjacent proton groups. Thus, considering the important changes in the chemical environment in the adjacent proton groups. Thus, considering plot δ ppm vs. pH for the signal corresponding to methylene protons adjacent to nitrogen atomsthe in plot δ ppm ring, vs. pH the signal the corresponding methylene protons adjacent to nitrogen atoms in piperazine wefor determined second pKa to (pK a2) for the compounds 3b and 4g (Figure 7B,D). piperazine ring, we determined the second pKa4g, (pKrespectively. 3b and (Figure 7B,D). a2 ) for the compounds The values of pKa2 were 5.72 and 6.69 for 3b and Unsurprisingly, the4gpK a2 values, for The values of pK were 5.72 and 6.69 for 3b and 4g, respectively. Unsurprisingly, the pK values, for a2 a2 both compounds, are lower than typical piperazine groups. This is because the compounds are both compounds, are lower than typical piperazine groups. This is because the compounds are tertiary tertiary amines. This type of amines are less basic than a secondary amine [60], concomitantly, the amines. This type amines aresubstituents less basic than a secondary concomitantly, inductive inductive effect ofof the distinct induces further amine lower [60], pKa values for boththe compounds. effect of the distinct substituents induces further lower pK values for both compounds. Additionally, Additionally, the pKa values predicted in-silico are close toa experimental values. All results reinforce the idea pKa values in-silico close to the that thepredicted compounds here are reported areexperimental weakly basic.values. All results reinforce the idea that the compounds here reported are weakly basic. 4.5. Radioligand Binding Studies 4.5. Radioligand Binding Studies Affinity of compounds at 5-HT6 receptors was evaluated using HEK-293 cells expressing human Affinity of compounds at 5-HT6 receptors 125 was evaluated using HEK-293 cells expressing 5-HT6R using the iodinated specific radioligand [ I]-SB-258585 (4-iodo-N-[4-methoxy-3-(4-methylhuman 5-HT6 R using the iodinated specific radioligand [125 I]-SB-258585 (4-iodo-N-[4-methoxy-3piperazin-1-yl)-phenyl]-benzenesulfonamide); Kd = 1.3 nM; 2200 Ci/mmol). Competitive inhibition (4-methyl-piperazin-1-yl)-phenyl]-benzenesulfonamide); Kd = 1.3 nM; 2200 Ci/mmol). Competitive assays were performed according to standard procedures, briefly detailed below. inhibition assays were performed according to standard procedures, briefly detailed below. Fractions of 45 μL of diluted 5-HT6 membrane preparation were incubated at 27 °C for 180 min Fractions 125 of 45 µL of diluted 5-HT6 membrane preparation were incubated at 27 ◦ C for 180 min with 25 μL of [125I]-SB-258585 (0.2 nM) and 25 μL of WGA PVT SPA beads (4 mg/mL), in the presence with 25 µL of [ I]-SB-258585 (0.2 nM) and 25 µL of WGA PVT SPA beads (4 mg/mL), in the presence of increasing concentrations (10−11 to 10−4 M) of the competing drug (5 μL) or DMSO, in a final volume of 100 μL of assay buffer (50 mM Tris, 120 mM NaCl, pH 7.4). Non-specific binding was determined by radioligand binding in the presence of a saturating concentration of 100 μM of clozapine. Binding of [125I]-SB-258585 to 5-HT6 receptors directly correlates to an increase in signal that was read on a Perkin Elmer Topcount NXT HTS (PerkinElmer Inc., Waltham, MA, USA). All compounds were tested at eight concentrations in triplicate. Clozapine was used as an internal standard for comparison. Data generated

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of increasing concentrations (10−11 to 10−4 M) of the competing drug (5 µL) or DMSO, in a final volume of 100 µL of assay buffer (50 mM Tris, 120 mM NaCl, pH 7.4). Non-specific binding was determined by radioligand binding in the presence of a saturating concentration of 100 µM of clozapine. Binding of [125 I]-SB-258585 to 5-HT6 receptors directly correlates to an increase in signal that was read on a Perkin Elmer Topcount NXT HTS (PerkinElmer Inc., Waltham, MA, USA). All compounds were tested at eight concentrations in triplicate. Clozapine was used as an internal standard for comparison. Data generated was analyzed using GraphPad Prism version 7.0 (GraphPad Software Inc., La Jolla, CA, USA). A linear regression line of data points was plotted, from which the concentration of competing ligand which displaces 50% of the specific binding of the radioligand (IC50 value) was determined and the Ki value was calculated based upon the Cheng-Prusoff equation: Ki = IC50 /(1 + L/Kd ) where L is the concentration of free radioligand used in the assay and Kd is the dissociation constant of the radioligand for the receptor. 4.6. Pharmacological Profile Determination Assays The pharmacologic profile of compounds was determined through an intracellular calcium mobilization assay [35] using a cloned human 5-HT6 -expressing cell line (HTS111RTA, Millipore, Temecula, CA, USA) according to the manufacturer0 s instructions with slight modifications. Immediately upon receipt, cells were placed in liquid nitrogen. Cells were thawed rapidly by removing from liquid nitrogen and immediately immersing in a 37 ◦ C water bath. Immediately after the ice thawed, the exterior of the vial was sterilized with 70% ethanol. One milliliter of pre-warmed Media Component was added to each vial of cells (Media Component was supplied along with 5-HT6 cells). Contents from two vials were placed into a 15 mL conical tube and the volume brought to 10 mL with Media Component. The cell suspension was centrifuged at 190× g for 4 min. Supernatant was removed and 10.5 mL of pre-warmed Media Component was added to resuspend the cell pellet. The cell suspension was seeded in black, clear-bottomed 96-well plates at a density of 50,000 cells in 100 µL volume per well. Plates were incubated at 37 ◦ C and 5% CO2 in an incubator overnight. Next day, the cells were loaded with Calcium 5 dye (R8186, Molecular Devices, Sunnyvale, CA, USA. Calcium 5 dye was made up according to the manufacturer0 s instructions in HEPES-buffered Hank0 s Balanced Salt Solution (HBSS) containing 5 mM probenecid at pH 7.4. Dye solution (90 µL) was added to the wells and incubated at 37 ◦ C for 1 h. The plates were then placed in the Flexstation whereupon 10 µL of test compound or DMSO control was added and the fluorescence (ex/em: 485/525 nm) monitored to determine whether the compounds were acting as agonists. The compounds were tested with a final concentration of 0.1% DMSO. Three minutes after addition of compounds the Flexstation added 50 µL of agonist 2-Me 5-HT at a final concentration of 500 nM and the fluorescence (ex/em: 485/525 nm) was monitored to determine whether the compounds were acting as antagonists. Dose-response curves and IC50 /EC50 values were generated using GraphPad Prism version 7.0 (GraphPad Software Inc., La Jolla, CA, USA). Values are the mean of duplicate data points. Error bars indicate standard error of the mean (SEM). 5. Conclusions In conclusion, we present the design, synthesis, and biological evaluation of novel extended N-arylsulfonylindole derivative compounds as antagonists of the 5-HT6 receptor. A convenient synthesis of the extended arylpiperazine derivatives was achieved to readily access diversely substituted analogues. Several of the tested compounds exhibited nanomolar affinity for the 5-HT6 receptor. Finally, two compounds 1-(1-(4-iodophenylsulfonyl)-1H-indol-3-yl)-2-(4-(2-methoxyphenyl)piperazin-1-yl)ethanol (4g) and 2-(4-(2-methoxyphenyl)piperazin-1-yl)-1-(1-(naphthalen-1-ylsulfonyl)-1H-indol-3-yl)ethanol (4j) showed strong inhibition of 2-Me-5HT-induced Ca2+ mobilization in a cell-based assay, suggesting that potent cellular activity may be induced through antagonism of the 5-HT6 receptor.

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Acknowledgments: This work was financially supported by FONDECYT INICIACION No. 11121418 grant to Gonzalo Recabarren-Gajardo. Carlos F. Lagos thanks OpenEye Scientific Software & ChemAxon for academic licenses of their software. Jaime Mella-Raipán thanks to FONDECYT INICIACION No. 11130701. Author Contributions: G.R-G formulated the research idea, designed the synthetic routes of compounds, analyzed the data and wrote the manuscript; C.F.L. performed the bioinformatics studies and wrote the manuscript; Compounds were synthesized and purified by G.R-G. undergraduate students G.V., S.A., F.F., and D.H.; J.M-R. contributed with the bioinformatics studies and manuscript preparation; G.V-C. participated in the bioinformatics studies; C.D.P-M. helped analyze the affinity results and contributed with organic reagents and analytical tools. R.M. contributed to determine the experimental pKa by NMR. Conflicts of Interest: The authors declare no conflict of interest.

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