Iron (III) Phosphate catalyzed the synthesis of 4-quinolones

New and efficient methods have been developed for the synthesis of 4-quinolones throughout Conrad–Limpach synthesis in diphenyl ether under reflux condition. This method possesses a various advantages such as using of green and versatile catalyst, easy procedure, work up and separation, without needing to column chromatography, and atom economic just removing ethanol as a byproduct. Also, the kind of solvent and reaction temperature has an important role in yield of reaction. When toluene, ethanol, acetonitrile and chloroform were subjected as solvent in ambient temperature and reflux condition, desired product did not result. Also when diphenyl ether was employed in room temperature, 100, 150 and 200 °C any product was obtained. Interestingly, desired product was resulted in good yield under reflux condition in diphenyl ether