Erlenmeyer-Plöchl Azlactone Synthesis

The Erlenmeyer–Plöchl azlactone synthesis is the preparation of azlactones (also called oxazolones) in a Z configuration (originally assigned to the E configuration) by condensation of aromatic aldehydes with hippuric acid (the benzoyl glycine derivatives) in the presence of acetic anhydride. The azlactones are useful for the synthesis of α‐ketos, a‐amino acids and peptides. The transacylation often occurs in this reaction, especially when the reaction mixture is refluxed.