The effect of substitution on anticonvulsant activity of some 5,5-diphenylhydantoin derivatives.

Some 5,5-diarylhydantoins and their 3-amino derivatives were synthesized as phenytoin analogs with enhanced rotational restriction of the benzene moieties. In preliminary pharmacological tests, the compounds symmetrically substituted in the benzene rings proved practically inactive as anticonvulsants. High and prolonged activity was observed with 3-amino-5,5-diphenylhydantoin.