Synthesis and antimicrobial activity evaluation of some substituted N'[arylidene]- 2-(3-methyl-5-pyridin-4-yl-1H-1,2,4-triazol-1-yl) acetohydrazide compounds

A new class of Schiff bases of 4-(3-methyl-1H-1,2,4-triazol-5-yl) pyridine was synthesized to meet structural requirements essential for the antimicrobial activity. 4-(3-methyl-1H-1,2,4-triazol-5-yl)pyridine was reacted with ethyl chloroacetate to form ethyl [3-methyl-5-(pyridin-4-yl)-1H-1,2,4-triazol-1-yl] acetate (2). Compound 2 was treated with hydrazine hydrate in methanol to yield 2-[3-methyl-5-(pyridin-4-yl)-1H-1,2,4-triazol-1-yl] acetohydrazide (3). The condensation of compound 3 with various aromatic aldehydes yielded the corresponding substituted N'-[arylidene]-2-(3-methyl-5-pyridin-4-yl-1H-1,2,4-triazol-1-yl) acetohydrazide (4a-j). The structural assessment of the newly synthesized Schiff bases (4a-j) was carried out by FT-IR, 1H-NMR, Mass spectra and elemental analysis. The target compounds 4a-j were screened for their in vitro antimicrobial activity and the Minimum Inhibitory Concentration of each compound was determined by liquid broth method. From newly synthesized series compounds 4b, 4c and 4h were exhibited significant antimicrobial potential against Staphylococcus aureus NCIM 2079, Escherichia coli NCIM 2065, Candida albicans NCIM 3471 and Aspergillus niger NCIM 1196