Synthesis and Biological Evaluation of Some New N1-[4-(4-Chlorophenylsulfonyl)benzoyl]-N4-(aryl)-thiosemicarbazides and Products of Their Cyclization

In the present study, new 1,2,4-triazoles, 1,3,4-thiadiazoles, and acylthiosemicarbaz-ides derived from 4-(4-chlorophenylsulfonyl)benzoic acid hydrazide were synthesized and screened for their antimicrobial and analgesic activities. Acylthiosemicarbazides 2-4 were synthesized by a reaction of 4-(4-chlorophenyl-sulfonyl)benzoic acid hydrazide 1 with different arylisothiocyanates.4,5-Disubstituted-2,4-dihydro-3H-1,2,4-triazol-3-thiones 5-7 and 2,5-disubstituted-1,3,4-thiadiazoles 8-10 were obtained by dehydrative cyclization of corresponding acylthiosemicarbazide derivatives 2-4 in basic media (8% aqueous sodium hydroxide) and in acidic media (sulfuric acid or phosphorous oxychloride), respectively. The structures of the newly synthesized compounds have been confirmed on the basis of elemental analysis and spectral studies (IR, H-1 NMR, C-13 NMR, MS). Their antimicrobial activities against some bacteria and yeasts were investigated. The analgesic activity of all compounds was performed with two pharmacological tests: the writhing test induced with acetic acid and hot-plate test. The results showed that triazole 7 had the best antimicrobial activity against Bacillus cereus. In the chemical stimulus test, triazoles 6 and 7 were the most active compounds whereas in the hot-plate test thiadiazoles 9 and 10 exhibited the highest analgesic activity. (C) 2013 Wiley Periodicals, Inc.