5-Benzylidenehydantoin → 5-(Phenylmethyl)-2,4-imidazolidinedione

Participants

Reaction Steps

190 g (1 mole) of 5-benzylidene-hydantoin are dissolved in 2 l of a N sodium hydroxide solution and 95 g of wet Raney-nickel are added. The hydrogen uptake is terminated after about 6-8 hours (the reaction mixture is shaken at atmospheric pressure). The catalyst is filtered off and washed with N sodium hydroxide. The filtrate is acidified to pH 3 with concentrated hydrochloric acid. The precipitated white crystals are filtered off, dried and washed with cold water. Thus 152 g of the desired compound are obtained, yield 80%. Mp.: 187°-189° C.

Provenance & Evidence