Synthesis and preliminary anticonvulsant activity evaluation of new 2-thioxo-4,5-imidazolidinedione derivatives.

A series of 1-substituted benzylideneamino-2-thioxo-3-allyl-4,5-imidazolidinediones (2a-j) were synthesized by the cyclization of 1-substituted benzylidene-4-allylthiosemicarbazides (1a-j) with oxalyl chloride in anhydrous ethereal medium. The structures of 2a-j were confirmed by analytical and spectral data (IR, 1H-NMR and EIMS). All synthesized compounds were evaluated for anticonvulsant activity against maximal electroshock (MES) and subcutaneous pentylenetetrazole (ScMet) induced seizures. Among the compounds tested, 2b and 2h exhibited some activity in anticonvulsant identification (Phase I) trials in mice.