Synthesis and anticonvulsant evaluation of some new 2-benzylsuccinimides

A series of 2-benzylsuccinimides (4a-f) were prepared for evaluation as potential anticonvulsants. Primary (Phase I) screening of these compounds indicated that succinimides 4d and 4e, containing lipophilic (+ pi), electron-withdrawing (+ sigma) phenyl substituents, were the most effective in controlling seizures induced by maximal electroshock (MES) and subcutaneous pentylenetetrazol (scMet). Compounds 4a, 4c, and 4d showed activity against scMet-induced seizures equal to that of their 2-phenylsuccinimide analogues and were somewhat more effective in the MES test. In quantitative (Phase II) testing, when administered ip in mice, 4d and 4e both demonstrated anticonvulsant potency superior to that of the prototype drug (ethosuximide) by the MES and scMet assays. However, they also exhibited greater neurotoxicity than ethosuximide in the rotorod test.