[6-oxo-3-(substituted phenyl)-5,6-dihydro-4H-pyridazine-1-yl] acetic acid hydrazide derivatives were synthesized from [6-oxo-3-(p-substituted phenyl)-5,6-dihydro-4H-pyridazine-1-yl] acetic acid ethyl ester. Friedal craft acylation of substituted aromatic hydrocarbon in the presence of anhydrous aluminium chloride yield b-( p-substituted benzoyl) propionic acid. After the reaction with hydrazine hydrate the b-(p-substituted phenyl) propionic acid yield 6-(p-substituted phenyl)-2,3,4,5-tetrahydro-pyridazine-3-one that on reaction with ethylbromoacetate yield ethyl ester of the appropriate pyridazinone. The final compounds were synthesized by reaction of [6-oxo-3-(p-substituted phenyl)-5,6-dihydro-4H-pyridazine-1-yl] acetic acid ethyl ester with hydrazine hydrate. The synthesized compounds were tested for anticonvulsant activity by MES (maximal electro shock) method.