Synthesis of imidazolidine 2,4 – dione derivatives

Synthesis routes to diphenyl hydantoin derivatives in the presence of the benzils; 4,4-dimethylbenzil , 4-methylbenzil , 4,4-bromobenzil , 4-dimethylaminbenzoin and 4-amin-4-nitrobenzoin and ure- give condensation of benzil and urea allowed by benzylic rearrangement.