Sturucture of an α-keto β-amido acid, 3-(phenylacetamido)pyruvic acid, and its methyl ester in the solid state and in organic and aqueous solvents

摘要

3-(Phenylacetamido)pyruvic acid and its methyl ester both exist in the enol from in the solid state and when dissolved in organic solvents. In aqueous solution, the pK_a's of the enol acid are 3.28 (CO_2H) and 10.14 (enolic OH) and that of the ester is 8.14 (enolic OH). The thermoldynamically stable form of both acid and ester in aqueous solution, however, is the keto sepcies. Ketonization rates of 3-(phenylacetamido)pyruvic acid were determined spectrophotometrically in acid and in buffered solution at neutral pH.