Amino acids as CH acids

Abstract

1. The formation of protonated and free Schiff's bases from S-alanine and salicylaldehyde was studied quantitatively by the PMR method in the interval of pD 9.0–12.0. 2. The rate constants of the racemization of S-alanine and its Schiffs base with salicylaldehyde protonated at the nitrogen were determined, and they were compared with the analogous constants for N-salicyl-idene-S-alaninate complexes of Cr(III), Rh(III), and Co(III) and the Schiffs base from pyridoxal and S-alanine. 3. The basic role of the metal in the model reactions consists of increasing the concentration of reactive particles in solution as a result of coordination of the Schiffs base with the metal ion.