Note on the Erlenmeyer Amino-acid Synthesis

THE series of reactions, constituting a general synthesis of a-amino-acids, devised by Erlenmeyer [1893] and since employed by many other workers, can be conducted, in most cases, with little trouble and excellent yields except at one stage. The condensation of an aromatic aldehyde with hippuric acid and the conversion of the resulting azlactone into the corresponding a- benzoylaminoacrylic acid proceed almost always in yields of 70 % or over.