Bronsted acidic ionic liquids catalyze the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives

A simple and facile method for the green synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives by direct three-component cyclo-condensation of isatoic anhydride, ammonium acetate (or primary amines), and arylaldehydes using different Bronsted acidic ionic liquids, for example 2-pyrrolidonium hydrogensulfate ([hnmp][HSO4]), N-methyl-2-pyrrolidonium hydrogensulfate ([NMP][HSO4]), and N-methyl-2-pyrrolidonium dihydrogenphosphate ([NMP][H2PO4]), as reusable catalysts under solvent-free conditions is described. In addition, reaction of anthranilamide and arylaldehydes for synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives was investigated.