Recyclization of 4,5-diphenyloxazolin-2-one and -2-thione under the influence of amines

4,5-Diphenyl-4-oxazolin-2-one and -2-thione undergo recyclization to 1-substituted 4,5-diphenyl-4-imidazolin-2-ones and -2-thiones, respectively, under the influence of primary amines. The action of hydrazine hydrate on the oxazolone leads to 5,6-diphenyl-1,2,3,4-tetrahydro-1,2,4-triazin-3-one. The corresponding ureas were isolated from the reaction mixtures in a number of cases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1028–1030, August, 1981.