The Coloration Reaction Mechanism of 6-Aminouracil Derivatives with Ehrlich Reagent and Its Application to the Colorimetric Determination Method. I
Kenichiro Nakashima · YAKUGAKU ZASSHI · 1977
The sequences of reactions between 6-aminouracil or its N-methylated derivatives and the Ehrlich reagent in the presence of acid catalysts were elucidated. In the first step, 6-aminouracils react with the Ehrlich reagent to form the labile Schiff bases, which are subsequently acid-hydrolyzed to the corresponding barbiturates. The latter reaction products condense again with the reagent to afford the corresponding stable benzylidene compounds. These reactions were found to be almost quantitative. The optimal experimental conditions were also established for utilizing the above reaction to the quantitative colorimetric determination of 6-aminouracils.