Improving lipase-catalyzed enantioselective ammonolysis of phenylglycine methyl ester in organic solvent by in situ racemization.

Lipase-catalyzed enantioselective ammonolysis of phenylglycine methyl ester was processed by in situ racemization with ammonium carbamate as the acyl acceptor. Using 1 mM benzaldehyde or 0.6 mM chloropyridoxal as the racemizing catalyst, 80% substrate conversion with an enantiomeric excess of the product of 95% were achieved at 20 degrees C after 7 h reaction.