Synthesis, characterization and antimicrobial evaluation of 3,5 diphenyl-1H- 1,2,4-triazole containing pyrazole function

In the present study 1-(3,5-diphenyl-1H-1,2,4-triazol-1-yl)ethanone (2) on condensation with various aromatic aldehydes in NaOH solution yielded the corresponding chalcones (3a-j). Chalcones on further reaction with isoncotinic acid hydrazide affords required [5-(substituted aryl)-3-(3,5-diphenyl-1H-1,2,4-triazol-1-yl)-4,5-dihydro-1H-pyrazol-1-yl](pyridin-4-yl) methanone (4a-j). The compounds were identified by spectral data analysis. All synthesized compound (3a-j and 4a-j) were screened for their in vitro antimicrobial activity by agar well method against S. aureus NCIM 2079, E. coli NCIM 2065, C. albicans NCIM 3471 and A. niger NCIM 1196. From newly synthesized series 2-chloro, 3-nitro, 4-methoxy, 4-hydroxy and 2,4-dimethoxy substituted compounds exhibited significant antimicrobial potential against the tested strains at 50μg/ml and 100μg/ml concentrations.