抄録
6-Amino-4-oxo-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine and its N- or S-substituted derivatives are hydrolyzed by p-toluenesulfonic acid or hydrochloric acid to the corresponding barbiturates. These barbiturates condense with the Ehrlich reagent in the presence of an acid catalyst to afford stable benzylidene compounds. These reactions were found to be almost quantitative. The optimal experimental conditions were also established for using the above reactions for the quantitative colorimetric determination of 6-amino-4-oxo-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine derivatives.
