One-Pot Tandem Approach for the Synthesis of Benzothiazoles from Benzyl Halides

Abstract

A one-pot tandem approach for the synthesis of benzothiazoles from benzyl halides and o-aminobenzenethiol was described. Benzothiazoles were obtained in high chemical yields under mild conditions in DMSO in the absence of an additional oxidant. Both benzyl chlorides and bromides bearing a range of substituents proved to be suitable substrates.

Key words

benzothiazole - benzyl halide - oxidation - one-pot - tandem reaction

References and Notes

• For selected examples, see:
• 1a Stevens MFG. McCall CJ. Lelieveld P. Alexander P. Richter A. Davies DE. J. Med. Chem.  1994,  37:  1689 
• 1b Aotsuka T. Abe N. Fukushima K. Ashizawa N. Yoshida M. Bioorg. Med. Chem. Lett.  1997,  7:  1677 
• 1c Loaiza-Pérez AL. Trapani V. Hose C. Singh SS. Trepel J. Stevens MFG. Bradshaw TD. Sausville EA. Mol. Pharmacol.  2002,  61:  13 
• 1d Trapani V. Patel V. Ciolino HP. Yeh GC. Hose C. Trepel JB. Stevens MFG. Sausville EA. Loaiza-Pérez AL. Br. J. Cancer  2003,  88:  599 
• 1e Leong CO. Suggitt M. Swaine DJ. Bibby MC. Stevens MFG. Bradshaw TD. Mol. Cancer Ther.  2004,  3:  1565 
• 1f Van Zandt MC. Jones ML. Gunn DE. Geraci LS. Jones JH. Sawicki DR. Srey J. Jacot JL. DiCioccio AT. Petrova T. Sawicki DR. Sredy J. Jacot JL. DiCioccio AT. Petrova T. Mitschler A. Podarny AD. J. Med. Chem.  2005,  48:  3141 
• 1g Huang S.-T. Hsei I.-J. Chen C. Bioorg. Med. Chem.  2006,  14:  6106 
• 1h Mortimer CG. Wells G. Crochard J.-P. Stone EL. Bradshaw TD. Stevens MFG. Westwell AD. J. Med. Chem.  2006,  49:  179 
• 2a Bradshaw TD. Matthews CS. Cookson J. Chew E.-H. Shah M. Bailey K. Monks A. Harrs E. Westwell AD. Wells G. Laughton CA. Stevens MFG. Cancer Res.  2005,  65:  3911 
• 2b Mukherjee A. Bradshaw TD. Westwell AD. Stevens MFG. Carmichael J. Martin SG. Br. J. Cancer  2005,  92:  30 
• 3a Miyamoto S. Exp. Opin. Ther. Patents  2002,  12:  621 
• 3b Suzen A. Buyukbingol E. Curr. Med. Chem.  2003,  10:  1329 
• 4 Bradshaw TD. Westwell AD. Curr. Med. Chem.  2004,  11:  1241 
• For recent reports, see:
• 5a Lewis JC. Berman AM. Bergman RG. Ellman JA. J. Am. Chem. Soc.  2008,  130:  2493 
• 5b Nandurkar NS. Bhanushali MJ. Bhor MD. Bhanage BM. Tetrahedron Lett.  2008,  49:  1045 
• 5c Yoshizumi T. Tsurugi H. Satoh T. Miura M. Tetrahedron Lett.  2008,  49:  1598 
• 5d Chou C.-H. Yu P.-C. Wang B.-C. Tetrahedron Lett.  2008,  49:  4145 
• 5e Ma HC. Jiang XZ. Synlett  2008,  1335 
• 5f Downer-Riley NK. Jackson YA. Tetrahedron  2008,  64:  7741 
• 5g Inamoto K. Hasegawa C. Hiroya K. Doi T. Org. Lett.  2008,  10:  5147 
• 5h Pratap UR. Mali JR. Jawale DV. Mane RA. Tetrahedron Lett.  2009,  50:  1352 
• 5i Miyaoku T. Mori A. Heterocycles  2009,  77:  151 
• 5j Pal S. Patra G. Bhunia S. Synth. Commun.  2009,  39:  1196 
• 5k Kumar A. Maurya RA. Ahmad P. J. Comb. Chem.  2009,  11:  198 
• 5l Canivet J. Yamaguchi J. Ban I. Itami K. Org. Lett.  2009,  11:  1733 
• 5m Hachiya H. Hirano K. Satoh T. Miura M. Org. Lett.  2009,  11:  1737 
• 6a Logemann W. Galimberti S. Tosolini G. Carneri I. Coppi G. Farmaco Ed. Sci.  1961,  16:  795 
• 6b Prescott B. Webb JM. Antibiot. Chemother.  1958,  8:  33 
• 6c Cossey HD. Gartside RN. Stephens FF. Arzneim. Forsch.  1966,  16:  33 
• 7a Chakraborti AK. Selvam C. Kaur G. Bhagat S. Synlett  2004,  851 
• 7b Rudrawar S. Kondaskar A. Chakraborti AK. Synthesis  2005,  2521 
• 7c Gupta SD. Singh HP. Moorthy NSHN. Synth. Commun.  2007,  37:  4327 
• 7d Seijas JA. Vazquez-Tato MP. Carballido-Reboredo MR. Crecente-Campo J. Romar-Lopez L. Synlett  2007,  313 
• 7e Zhu X.-Q. Zhang M.-T. Yu A. Wang C.-H. Cheng J.-P. J. Am. Chem. Soc.  2008,  130:  2501 
• 7f Sharghi H. Asemani O. Synth. Commun.  2009,  39:  860 
• 8a Itoh T. Nagata K. Ishikawa H. Ohsawa A. Heterocycles  2004,  62:  197 
• 8b Itoh T. Nagata K. Ishikawa H. Ohsawa A. Heterocycles  2004,  63:  2769 
• 8c Kawashita Y. Ueba C. Hayashi M. Tetrahedron Lett.  2006,  47:  4231 
• 8d Chen Y.-X. Qian L.-F. Zhang W. Han B. Angew. Chem. Int. Ed.  2008,  47:  9330 
• 9 Bahrami K. Khodaei MM. Naali F. J. Org. Chem.  2008,  73:  6835 
• 10 Wilfred CD. Taylor RJK. Synlett  2004,  1628 
• For seminal reports and reviews, see:
• 11a Kornblum N. Powers JW. Anderson GJ. Jones WJ. Larson HO. Levand O. Weaver WM. J. Am. Chem. Soc.  1957,  79:  6562 
• 11b Kornblum N. Jones WJ. Anderson GJ. J. Am. Chem. Soc.  1959,  81:  4113 
• 11c Epstein WW. Sweat FW. Chem. Rev.  1967,  67:  247 
• 11d Mancuso AJ. Swern D. Synthesis  1981,  165 
• 11e Tidwell TT. Synthesis  1990,  857 
• 11f Tidwell TT. Org. React.  1990,  39:  297 
• 12 For related study for the preparation of benzoxazoles, see: Blacker AJ. Farah MM. Marsden SP. Saidi O. Williams JMJ. Tetrahedron Lett.  2009,  50:  6106 

13

Treatment of benzaldehyde with o-aminothiophenol under the same reaction conditions gave the corresponding benzothiazole in 80% yield.

14

o-Aminophenol was not a suitable substrate and the corresponding benzoxazole was furnished in low yield under the same conditions.

15

General Experimental Procedure A mixture of benzyl halide (0.24 mmol, 1.2 equiv) with NaHCO₃ (1 mmol, 5.0 equiv) in DMSO (2 mL) was stirred for 5 h at 90 ˚C. Then, o-aminothiophenol (0.2 mmol, 1.0 equiv) was added into the above solution. Resulting solution was continued stirring for overnight up to the completion of the reaction. The reaction mixture was cooled to r.t. and was extracted with EtOAc. The combined organic layers were successively washed with H₂O and brine, dried over anhyd Na₂SO₄, and concentrated to dryness. The crude product was purified by preparative TLC on silica gel to give the product.