Synthesis, study of structure activity relationship and evaluation of biological activities of substituted (E)-2-Benzylidene-N-Methylhyrazinecarbothioamides

Abstract

A series of ten substituted (E)-2-benzylidene-N-methylhydrazinecarbothioamides were synthesized from 4-methyl-3-thiosemicarbazide with substituted benzaldehydes. All the synthesized compounds were in good agreement with elemental and spectral data (UV, FT-IR, 1H NMR and 13C NMR). The assigned UV λmax (nm), IR νC=N (cm-1), NMR δ1H (ppm) CH=N and δ13C (ppm) C=N spectral data of (E)-2-benzylidene-N-methylhydrazinecarbothioamides correlated with Hammett constants using single and multi-regression analysis. From the results of correlation analysis substituent effects on the spectral data have been discussed. The antibacterial activity of (E)-2-benzylidene-N-methylhydrazinecarbothioamides have been studied with three Gram-positive pathogenic bacterial strains namely (B. subtilis, S. aureus and S. pyogens) and two Gram-negative strains (E. coli and P. aeruginosa). The antifungal activity of (E)-2-benzylidene-N-methyl hydrazones studied with three fungal species (A. flavus, A. niger, T. viride) using disk diffusion method.