acidic brønsted ionic liquids catalyzed the preparation of 2-amino-3-cyanopyridine derivatives under ambient and solvent-free conditions

The acidic ionic liquids, 2-pyrrolidonium hydrogensulfate, n-methyl-2-pyrrolidonium hydrogensulfate, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate and (4-sulfobutyl) tris (4-sulfophenyl) phosphonium hydrogensulfate catalyzed one-pot four-component condensation between aromatic aldehydes, substituted acetophenones, malononitrile and ammonium acetate to afford corresponding 2-amino-3-cyanopyridine derivatives. this synthetic method has the remarkable advantages such as mild reaction conditions and good isolated yields, short reaction time, and use of green catalysts.