Ring transformations of 1,3,4‐oxadiazol‐2(3<i>H</i>)‐one derivatives into 1‐amino and 1,3‐diamino‐2,4‐imidazolidinedione (hydantoin) derivatives

Abstract

Abstract Some ethyl 5‐aryl(or benzyl)‐2‐oxo‐1,3,4‐oxadiazole‐3(2 H )‐acetates were prepared and treated with ammonia, primary amines or hydrazine to give 1‐amino‐2,4‐imidazolidinedione or 1,3‐diamino‐2,4‐imidazolidinedione derivatives. The 1,3‐bis(benzylideneamino)‐2,4‐imidazolidinedione was obtained by reacting ethyl bromoacetate with the 1,5‐dibenzylidenecarbonohydrazide sodium salt.