Synthesis of hydroxyacetic acid and its esters from glyoxal catalyzed by multivalent metal ions

Hydroxyacetic acid was produced from an aqueous solution of glyoxal in the presence of a catalytic amount of multivalent metal ion by heating the solution at temperatures of 160-200 degrees C. Hydroxyacetic acid ester was also produced from an alcoholic glyoxal solution by the same procedure as that of the aqueous glyoxal solution. Aluminum ion and oxyzirconium ion were active and selective catalyst, whereas ions of lead, manganese, cerium, lanthanum, zinc, cadmium, magnesium, and cobalt showed little or no appreciable activity and selectivity. Catalytic activities of ions of copper, nickel, chromium and iron were in between those of ions of aluminum and lead. The reaction is intramolecular Cannizaro type reaction with a yield of up to 94%. The obtained acid, which is distinct from conventional Cannizaro reactions, is in the form of free acid. This is the distinguished feature of the reaction. The reaction scheme is proposed.