Synthesis of some 4-(alkylidene/arylidene)amino-2,4-dihydro-5- (2-thienyl)-3H-1,2,4-triazole-3-thiones tested for antimicrobial activity.

A series of 4-(alkylidene/arylidene)amino-2,4-dihydro-5- (2-thienyl)-3H-1,2,4-triazole-3-thiones (2a-h) were synthesized. The structural elucidation of all the compounds was made on the basis of analytical and spectral data (IR, 1H-NMR and EIMS). All synthesized compounds were evaluated for in vitro antimicrobial activity against various bacteria and fungi. Some of the compounds demonstrated antimicrobial activity against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Trichophyton rubrum, Trichophyton mentagrophytes var. erinacei NCPF-375 and Microsporum canis (MIC 50-6.25 mg/ml). The in vitro antimycobacterial activity of the new compounds was also investigated. Some of the compounds showed varying degrees of inhibition (2-40%) against Mycobacterium tuberculosis H37Rv in the primary screen that was conducted at 12.5 mg/ml using the BACTEC 460 radiometric system.