Ionic Liquid Catalyzed Expeditious Synthesis of 2-Aryl-2,3-dihydroquinolin-4(1H)-ones and 2-Aryl-2,3-dihydro-4H-chromen-4-ones under Microwave Irradiation

A facile and convenient synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-one and 2-aryl-2,3-dihydro-4H-chromen-4-one has been described using ionic liquid catalyzed intramolecular cyclization of the corresponding 2'-aminochalcones and 2'-hydroxychalcones, respectively. The rapid and fairly general protocol affords product in good yield. Ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, was recovered and reused without loosing its efficiency.