Rapid microwave-enhanced synthesis of 4-hydroxyquinolinones under solvent-free conditions

3-Aryl-4-hydroxyquinolin-2(1H)-ones are potent and selective glycine-site NMDA receptor antagonists of pharmaceutical interest. A novel microwave-enhanced synthesis of such quinolinones under solvent-free conditions has been developed. The quinolinones are easily obtained in a one-pot procedure as a result of the formal amidation of a malonic ester derivative with an aniline and subsequent cyclisation of the intermediate malondianilides.