Abstract
The equiliblium constants of pyridoxal- and pyridoxal phosphate-Schiff bases are determined by an optical method and the pH dependence of the Schiff bases is analysed. These results suggest that aromatic pyridoxal-Schiff bases are unstable compared with aliphatic pyridoxal-Schiff bases and the stability of pyridoxal phosphate-Schiff bases decreases at high pH value. These and the other factors affecting the stability of the Schiff bases are discuseed. These compound served as a key intermidiate in the synthesis of pyridoxal-5-phosphate.
