4-(Isatin-3-ylideneamino) benzoic acid, was synthesized and converted into 4- (isatin-3-ylideneamino) benzoyl chloride. Hydrazinolysis of the acid chloride afforded4- (isatin-3-ylideneamino) benzohydrazide. The latter compound was used as a key precursor for the synthesis of pyrazole, triazole, phthalazine, thiadiazole, and oxadiazole derivatives via its reaction with different electrophilic reagents. Structures of all synthesized compounds were elucidated from FT-IR, 1H-NMR, mass spectroscopy and elemental analyses.