Synthesis and antiviral activity of 5-(4-chlorophenyl)-1,3,4- thiadiazole sulfonamides

Abstract

Starting from 4-chlorobenzoic acid, 10 new 5-(4-chlorophenyl)-N- substituted-N- 1,3,4-thiadiazole-2-sulfonamide derivatives were synthesized in six-steps. Esterification of 4-chlorobenzoic acid with methanol and subsequent hydrazination, salt formation and cyclization afforded 5-(4-chlorophen-yl)-1,3, 4-thiadiazole-2-thiol (5). Conversion of this intermediate into sulfonyl chloride 6, followed by nucleophilic attack of the amines gave the title sulfonamides 7a-7j whose structures were confirmed by NMR, IR and elemental analysis. The bioassay tests showed that compounds 7b and 7i possessed certain antitobacco mosaic virus activity. © 2010 by the authors; licensee MDPI, Basel, Switzerland.