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

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, 1 H NMR and 13 C NMR). The assigned UV λ max (nm), IR νC=N (cm -1 ), NMR δ 1 H (ppm) CH=N and δ 13 C (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. f lavus , A. niger , T. viride) using disk diffusion method.