Synthesis and physicochemical properties of new derivatives of alpha-substituted gamma-phthalimidobutyric acid are described. N-substituted amides of alpha-(4-phenylpiperazine)-gamma- phthalimidobutyric acid were prepared by condensation of the acid with the corresponding derivatives of benzylamine in the presence of BOP reagent. 2-(4-Phenylpiperazine)- or 2-(4-benzylpiperidine)-4-phthalimidobutyric acid were esterified with alkyl bromide in the presence of DBU or tetrabutylammonium bromide as catalyst. The obtained compounds were evaluated for anticonvulsant activity. 2-(4-Phenylpiperazine)-4-phthalimidobutyric acid and three N-substituted amides of this acid displaced protection against MES and scMet-induced seizures.