Selective heterogeneous catalytic hydrogenation of nitriles to primary amines in liquid phase

A method for selective liquid-phase heterogeneous catalytic hydrogenation of nitriles to primary amines has been developed. Benzonitrile (BN) was hydrogenated to benzylamine (BA) under mild reaction conditions (30 °C, 6 bar), over supported palladium catalysts, in a mixture of two immiscible solvents (e.g. water/dichloromethane) and in the presence of sodium dihydrogen phosphate (NaH2PO4). Complete conversion, very high selectivity (95% to BA) and isolated yield (85-90%) could be achieved by using this process. Very pure product (>99% BA-content) was prepared without applying any special purification procedures.