Abstract

The reaction of some 5-acylaminopyrimidines, having 4-oxo groups, with phosphorus oxychloride or phosphorus pentasulfide leads to the oxazolo- or thiazolo -[5,4-d] pyrimidines respectively. The condensation of amidinothiourea with pentane-2,4-dione leads to 1-(4,6-dimethylpyrimidin-2-yl)urea directly, and subsequent reaction with diethyl acetylene- dicarboxylate gives a thiazolylaminopyrimidine . The synthesis of some other pyrimidinylureas and thioureas has also been carried out.