抄録
Unsymmetrical di-substitution products of urea do not give N, N, N'-ri-substitution produts by the reaction with primary amines from its reaction mechanism. However, a mono- or di-substituted urea with the primary amines was formed by the exchange reaction of a secondary amine liberated on the thermal dissociation of unsymmetrical disubstitution product of urea, with primary amines. In the most cases the reaction of unsymmetrical di-substitution products of urea with amines gives a mono or di-substituted urea with the primary amines. Further reaction of the mono or di-substituted urea with the secondary amine gave N, N, N'-tri-substituted urea in some cases.
