Zinc dust catalysed efficient synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones

Abstract

A straight forward synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (also called azlactones) by the condensation of arylaldehyde with hippuric acid in the presence of acetic anhydride and zinc dust as aheterogeneous catalyst is described. The reaction proceeds rapidly, does not require any additives and has a significantly shorter reaction rate. In the present method, aromatic aldehydes and hippuric acid have been successfully applied to synthesize various substituted azlactones in good to excellent yields. The final product has been characterised by FT-IR, ¹H and ¹³C NMR, and mass spectrometry.