Solventless Regeneration of Ketones from ...

Synthetic Communications

ISSN: 0039-7911 (Print) 1532-2432 (Online) Journal homepage: http://www.tandfonline.com/loi/lsyc20

Solventless Regeneration of Ketones from Thioketones using Clay Supported Nitrate Salts and Microwave Irradiation Rajender S. Varma & Dalip Kumar To cite this article: Rajender S. Varma & Dalip Kumar (1999) Solventless Regeneration of Ketones from Thioketones using Clay Supported Nitrate Salts and Microwave Irradiation, Synthetic Communications, 29:8, 1333-1340, DOI: 10.1080/00397919908086108 To link to this article: http://dx.doi.org/10.1080/00397919908086108

Published online: 17 Sep 2007.

Submit your article to this journal

Article views: 37

View related articles

Citing articles: 19 View citing articles

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=lsyc20 Download by: [Fordham University]

Date: 13 November 2015, At: 06:13

SYNTHETIC COMMUNICATIONS, 29(8), 1333-1340 (1999)

Downloaded by [Fordham University] at 06:13 13 November 2015

SOLVENTLESS REGENERATION OF KETONES FROM THIOKETONES USING CLAY SUPPORTED NITRATE SALTS AND MICROWAVE IRRADIATION

Rajender S. Varma* and Dalip Kumar Department of Chemistry and Texas Research Institute for Environmental Studies Sam Houston State University, Huntsville, TX 77341-2117, USA E-mail: CHM-RSV@ SHSU.EDU

Abstract: Thioketones are readily converted into the corresponding ketones under solvent-free conditions using clayfen or clayan in a process that is accelerated by microwave irradiation.

There are several reagents developed for the transformation of thioketones to ketones1 such as trifluoroacetic anhydride,la CuCl/MeOH/NaOH, 1 b tetrabutylammonium hydrogen sulfate/NaOH,1C clay/ferric nitrate,ld NOBF4,le bromate and iodide solutions, alkaline hydrogen peroxide,lg sodium peroxide,lh bases e.g. KOBu,li thiophosgene,lJ DMSO,lk,ll trimethyloxonium fluoborate,lm tellurium based 'oxidants,ln710 photochemical transformations,lP dimethyl selenoxide,lq benzeneseleninic anhydride, lr benzoyl peroxide,ls halogen-catalyzed alkoxides under phase transfer conditions,lt NaN02/HCl,lu Hg(OAc)2,1V

*To whom correspondence should be addressed. 1333 Copyright 0 1999 by Marcel Dekker, Inc.

www.dekker.com

VARMA AND KUMAR

1334

SOC12/CaC031* and singlet oxygen.lx The above described efforts, however, have certain limitations such as the use of the stoichiometric amounts of the oxidants which are often inherently toxic or require longer reaction time or involve tedious procedure.1 Recently the use of supported reagents2 and especially those assisted by microwave irradiation,5>6has gained special attention because of their environmental friendly nature, simple work-up procedure and rapid reaction rates. Downloaded by [Fordham University] at 06:13 13 November 2015

In continuation of our ongoing program to develop benign and expeditious methods for organic transformation under solvent-free conditions using microwave irradiations and the interest in green chemistry theme with growing emphasis on pollution prevention? we have achieved the dethioacetalization of carbonyl compounds using clay supported iron (III) nitrate (clayfen).68 A recent report on the use of related reagent, clayan8 (ammonium nitrate impregnated on clay), prompts us to report our results on the efficient regeneration of the ketones from thioketones using either of the above clay supported nitrate salts coupled with microwave thermolysis. We find that the thioketones are rapidly converted into their parent ketones using either clayfen or clayan upon microwave thermolysis (1-2min). Both the reagents are effective in this transformation but the yields are

comparatively higher in the case of clayfen. The reaction with clayan, however, is exothermic above 55 "C and requires good control of bath temperature; poor yields of products are obtained above 55 OC. The scope of these reactions are investigated for a wide variety of thioketones including thioflavones. Our results are summarized in the Table.

That the effect may not be purely thermar) is borne out by the fact that using an alternate heating mode (oil bath) at Same temperature of 1 10°C clayfen requires 1.5 h for completion of the reaction. However, in case of clayan at the same

temperature of 55 OC the starting material remains unchanged even after 24 h.

1335

REGENERATION OF KETONES

Table: Solvent-free transformation of thioketones to ketones by clayfen or clayan and microwave irradiation . Substrates

Downloaded by [Fordham University] at 06:13 13 November 2015

Entry

Products

Clavfen (ClayanY Time (set) Yields(%)b

&

2

n

4

5

Br

fl \

6

120(90)

91(84)

120(90)

89 (86)

S

7

aResults in the parenthesis correspond to the reactions conducted with clayan. bYields refer to the isolated products which are identified by comparison of their m.p./b.p.,IR and TLC with those of the authentic samples.

1336

VARMA AND KUMAR

In conclusion, the microwave thermolysis of thioketones with clay supported nitrate salts, "clayfen or clayan," is inexpensive and convenient protocol for the rapid regeneration of ketones under solvent-free and mild conditions.

Experimental Section The reagents and chemicals were obtained from AIdrich Chemical Co. and Downloaded by [Fordham University] at 06:13 13 November 2015

were used as received without further purification. A Sears Kenmore microwave oven (900 Watts) equipped with a turntable was used for microwave heating. TLC was performed on silica gel plates supplied by Analtech using Hexane:EtOAc (8:2, v/v) as the solvent system. Melting points were determined on a Mel-Temp I1 hot stage apparatus using Fluke 51 WJ digital thermometer and are uncorrected. The IR spectra were recorded on a Perkin-Elmer 1310 spectrophotometer and IH N M R spectra were recorded in CDC13 on Varian (60 MHz) or Jeol (300 MHz) spectrometers using TMS as an internal standard. Thioketones,lo thioflavones,ll clayfen12 and clayan8 were prepared according to the literature procedures.

General Method: Clayfen (0.33 g) or clayan (0.56 g) was throughly mixed with thioketone (lmmol ) in the solid state using a pestal and mortar. The material was tranferred into a test tube and placed in a alumina bath inside the microwave oven and irradiated (1-2 min.). Upon completion of the reaction, monitored on TLC (Hexane:EtOAc, 8:2, v/v), the product was extracted into methylene chloride. Remove1 of the solvent under reduced pressure afforded pure ketones (Table).

Acknowledgment: We are grateful for financial support to the Texas Advanced Research Program (ARP) in chemistry (Grant # 003606-023) and Texas Regional Institute for Environmental Studies (TRIES).

1337

REGENERATION OF KETONES

References and notes 1.

(a) Masuda, R.; Hojo, M.; Ichi, T.; Sasano, S.; Kobayashi, T. and Kuroda, C. Tetrahedron Lett. 1991, 32, 1195. (b) Narasimhamurthy, N. and Samuelson, A.G. Tetrahedron Lett. 1986, 27, 3911. (c) Alper, H.; Kwiatskowska, C.; Petrignani, J.F. and Sibtain, F. Tetrahedron Lett. 1986, 27,5449. (d) Chalais, S.; Cornelis, A.; Laszlo, P. and Mathy A. Tetrahedron

Downloaded by [Fordham University] at 06:13 13 November 2015

Lett. 1985, 26, 2327. (e) Olah, G.A.; Arvanaghi, M.; Ohannesian, L. and

Surya Prakash G.K. Synthesis 1984, 785. (f) Capps, H.H. and Dehn, W.M. J. A m Chem. SOC. 1932, 54, 4301. (g) Kalm, M.J. J. Org. Chem. 1961, 26, 2925. (h) Loh, R.T.C. and Dehn W.M. J. Am. Chem. SOC. 1926, 48, 2956. (i) Gompper, R.Y. and Elser, W. LiebigsAnn. Chem., 1969, 725, 64. (Chem. Abstr. 1969, 71, 90728). (i) Abuzar, S.; Sharma,

S. and lyer, R.N. Indian J. Chem. Sec B 1980, 19, 211. (k) Mikolajczyk, M. and Luczak, J. Synthesis 1974, 491. (1) Mikolajczyk, M. and Luczak, J. Synthesis 1975, 114. (m) Mukherjee, R. Indian J. Chem Sec. B 1977,

15, 502. (n) Barton, D.H.R.; Ley, S.V. and Meerholz, C.A. J. Chem. Soc., Chem. Commun. 1979, 755.

(0)Ley,

S.V.; Meerholz; C.A. and Barton,

D.H.R. Tetrahedron Lett. 1980, 1785. (p) Gano, J.F. and Atik, S. Tetrahedron Lett. 1979, 4635. (9) Mikolajczyk, M. and Luczak, J. J. Org. Chem. 1978,43, 2132. (r) Cussans, N.J.; Ley, S.V. and Barton, D.H.R.

J. Chem. SOC., Perkin Trans. 1 1980, 1650. (s) Vaino, L. and Schinuer, A. Chem. Ber. 1914, 47, 699. (t) Singh, H.; Singh, P. and Malhotra, N. J . Chem SOC.Perkin Trans. 1 1981, 2647. (u) Jorgensen, K.A.; Ghattas,

A.-B.A.G. and Lawesson, S.O. Tetrahedron 1982, 38, 1163. (v) Mastalerz, H. and Gibson, M.S. J . Chem SOC. Perkin I 1981, 2952. (w) Son, N.K.;

Pinel, R. and Mollier, Y. Bull. Chem. SOC. France. 1974, 1359. (x) Woman, J.J.; Shen, M. and Nichols, P.C. Can. J. Chem. 1972, 50, 3923.

VARMA AND KUMAR

1338

2.

(a) McKillop, A. and Young, D.W. Synthesis 1979,401;481.(b) Balogh, M. and Laszlo, P. “Organic Chemistry Using Clays, ” Springer-Verlag, Berlin, 1993. (c) Clark, J.H. “Catalysis of Organic Reactions by Supported Inorganic Reagents, ” VCH Publisher, Inc., New York, 1994.

3.

(a) Gedye, R.; Smith, F.; Westaway, K.; Ali, H.; Baldisera, L.; Laberge, L.

Downloaded by [Fordham University] at 06:13 13 November 2015

and Rousell, J. Tetruhedron Lett. 1986,27,279.(b) Giguere, R.J.; Namen, A.M.; Lopez, B.O.; Arepally, A.; Ramos, D.E.; Majetich, G. and Defrauw, J. Tetruhedron Lett. 1987,28,6553.

4. For reviews on MW-assisted reactions see: (a) Caddick, S. Tetrahedron 1995,5Z,10403. (b) Varma, R.S. “Microwave-Assisted Reactions under Solvent-Free ‘Dry’ Conditions” in Microwaves: Theory and Application in Material Processing ZV, Clark, D.E.; Sutton, W.H. and Lewis, D.A., Eds.,

American Ceramic Society, Ceramic Transactions 1997,80,pp 357-365.

5.

(a) Oussaid, A.; Thach, L.N. and Loupy, A. Tetrahedron Lett. 1997,38,

2451. (b) Villemin, D. and Benalloum, A. Synth. Commun. 1991,2Z,63. 6. For cleavage-deprotection reactions see: (a) Varma, R.S.; Chatterjee, A.K. and Varma, M. Tetrahedron Lett. 1993,34, 3207. (b) Varma, R.S.; Chatterjee, A.K. and Varma, M. Tetrahedron Lett. 1993,34,4603.

(c) Varma, R.S.; Varma, M. and Chatterjee, A.K. J. Chem. SOC., Perkin Trans. I 1993, 999. (d) Varma, R.S.; Lamture, J.B. and Varma, M. Tetrahedron Lett. 1993,34, 3029. (e) Varma, R.S. and Saini, R.K. Tetrahedron Lett. 1997,38,2623. (f) Varma, R.S. and Meshram, H.M. Tetrahedron Lett. 1997,38,5427.(8) Varma, R.S. and Meshram, H.M. Tetrahedron Lett. 1997,38, 7973. (h) Varma, R.S.; Dahiya, R. and Saini,

R.K. Tetrahedron Lett. 1997,38,8819. For condensation-cyclization reactions see: (i) Varma, R.S.; Dahiya, R. and Kumar, S. Tetruhedron Lett.

1997,38,2039. (j) Varma, R.S. and Dahiya, R. Synlett 1997, 1245.

REGENERATION OF KETONES

1339

(k) Varma, R.S.; Dahiya, R. and Kumar, S. Tetrahedron Lett. 1997.38,

5131. (1) Varma, R.S. and Saini, R.K. Synlett 1997, 857. (m) Varma, R.S. and Dahiya, R. J. Org. Chem. 1998, (in press). For oxidation reactions see: (n) Varma, R.S. and Dahiya, R. Tetrahedron Lett. 1997,38, 2043. (0)Varma,

R.S.; Saini, R.K. and Meshram, H.M. Tetrahedron Lett. 1997,

38,6525. (p) Varma, R.S.; Dahiya, R. and Saini, R.K. Tetrahedron Lett. Downloaded by [Fordham University] at 06:13 13 November 2015

1997,38, 7029. (q) Varma, R.S.; Saini, R.K. and Dahiya, R. Tetrahedron Lett. 1997, 38, 7823. (r) Varma, R.S.; Dahiya, R. and Saini, R.K. Tetrahedron Lett. 1997, 38, 7029. (s) Varma, R.S. and Dahiya, R. Tetrahedron Lett. 1998,39, 1307. (t) Varma, R.S.; Dahiya, R. and Kumar, D. Molecules Online 1998, 2, 82. (u) Varma, R.S. and Saini, R.K. Tetrahedron Lett. 1998, 39, 1481. (v) Varma, R.S.; Saini, R.K. and Dahiya, R. J. Chem. Res. ( S ) 1998, 120. (w) Varma, R.S. and Naicker, K.P. Molecules Online 1998,2,94. For reduction reactions see: (x) Varma, R.S. and Saini, R.K. Tetrahedron Lett. 1997,38,4337. (y) Varma, R.S. and Dahiya, R. Tetrahedron 1998,54, 6293. (z) Varma, R.S. and Naicker, K.P. Tetrahedron Lett. 1998, (in press). 7.

Benign by Design. Alternative Synthetic Design for Pollution Prevention, ACS Symposium Series 577, Anastas, P.T. and Farris, C.A. (Eds.), American Chemical Society, Washington, DC 1994.

8.

Meshram, H.M.; Reddy, G.S. and Yadav, J.S. Tetrahedron Lett. 1997,38, 8891.

9.

The temperature of the reaction mixture inside the alumina bath reached -1 10 O C after 1.5 min. in a MW oven operating at its full power (900 Watts).

10. Pedersen, B.S.; Scheibye, S.; Nilsson, N.H. and Lawesson, S.O. Bull. SOC.

Chim. Belg. 1978,87, 223.

1340

11. Levai, A.J. 3. Chem. Rex (S)1992, 163. 12. Cornelis, A. and Laszlo, P. Synthesis 1985,909.

Downloaded by [Fordham University] at 06:13 13 November 2015

(Received in tht USA 13 October 1998)

VARMA AND KUMAR