Synthesis, characterization, and antimicrobial activity of some new N-aryl-N'-(2-oxoindolin-3-ylidene)-benzohydrazonamides

A green approach was developed for synthesizing a series of (isatin-3-ylidene)-hydrazonamides 3a-j from the reaction between isatin, (isatin-3-ylidene)malononitrile, or 2-cyano-2-(2-isatin-3-ylidene)acetate and benzohydrazonamide in ethyl acetate solutions at ambient temperature. The structures of the new compounds were confirmed on the basis of spectral data. In this eco-friendly medium, a variety of (isatin-3-ylidene)hydrazonamides were obtained free of catalyst in good to excellent yields. All the synthesized products were evaluated for their antimicrobial activity. Among the compounds tested, 3b and 3d exhibited good antibacterial activity against Staphylococcus aureus, whereas others responded moderately with reference to the standard drug ciprofloxacin.