The zwitterionic imidazolium salt: First used for synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones under solvent-free conditions

Abstract

The zwitterionic imidazolium salt was prepared and characterized by 1H NMR. It was first used for synthesis of azlactones via Erlenmeyer synthesis from aromatic aldehydes and hippuric acid under solvent-free conditions. It was found that aldehyde substituents play an important role in these reactions. Better conversions and therefore higher isolated yields were observed when electron-withdrawing groups (EWG-) were present in the aromatic aldehyde. Opposite results were shown when electron-donating groups (EDG-) were present in the aromatic aldehyde. However, azlactones were obtained in moderate to high yields. © 2013 Baocheng Zhou and Wenxing Chen.