Pharmacological evaluation and characterizations of newly synthesized 1,2,4-triazoles

The triazole analogs were obtained via. multistep synthesis sequence beginning with ethyl nicotinoate 3 which on treatment with hydrazine hydrate yields nicotinoyl hydrazide 4. Intermolecular cyclisation of 4 with 4-methylbenzoic acid in presence of phosphorous oxy chloride affords 2-(3-pyridyl)-5-(4-methylphenyl)-1,3,4-oxadiazole 5. Condensation of 5 with various substituted 2-hydrazino benzothiazole 2a-j results in 3-(3-pyridyl)-5-(4-methylphenyl)-4-(N-substituted-1,3-benzothiazol-2-amino)-4H-1,2,4-triazole 6a-j analogs. All the compounds have been characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and mass spectral data. In vitro antitubercular activity was carried out against Mycobacterium tuberculosis H(37)Rv strain using Lowenstein-Jensen medium and antimicrobial activity against various bacteria and fungi using broth microdilution method. Compounds 2e, 6a, 6b, 6c, 6d, 6g, 6h and 6i emerged as promising antimicrobials. It was also observed that the promising antimicrobials have proved to be better antituberculars. Compound 6j showed better antitubercular activity compared to rifampicin. (C) 2010 Elsevier Masson SAS. All rights reserved.