Potent Anticonvulsant 1H-Imidazol-5(4H)-One Derivatives with Low Neurotoxicity

We report here the synthesis and in vivo anticonvulsant/neurotoxicity activities of a series of compounds belonging to 2-aryl-4-arylidene-1-phenyl-1H-imidazol-5(4H)-one. The scaffold is based on the commonality of 5-membered lactam ring structures as successful anticonvulsant agents. The present compounds exhibited a range of anticonvulsant activity in pentylenetetrazole (PTZ)-induced seizure test. In particular, the protection was excellent by compounds bearing furylmethylidene on C4, possibly due to good pharmacokinetic properties. It was found that high lipophilicity and/or electron deficient aryl ring substitution at C4 compromised the anticonvulsant activities. For example, chloro analogues were found much less active than unsubstituted phenyl or furyl derivatives. Regarding side effects, active compounds exerted no observable neurotoxic effect at their therapeutic doses in Chimney test.