Highly selective hydrogenation of 2-chloro-5-cyanopyridine with an improved sponge nickel catalyst

A practical synthesis of (6-chloropyridin-3-yl)methylamine (1), a key inter mediate of neo-nicotinoide insecticides 2, was achieved by highly selective hydrogenation of 2-chloro-5-cyanopyridine (3). The hydrogenation of 3 with an improved Sponge nickel catalyst, prepared from an alloy of low nickel c ontent (Ni 38%, Al 62%) and subjected to heat treatment in water, wits carr ied out at 50 degrees C and 1.2-1.4 kg/cm(2) hydrogen pressure to give 1 in 86% yield and (pyridin-3-yl)methylamine (4), a dechlorinated by-product, i n only 2% yield. (C) 1999 Elsevier Science Ltd. All rights reserved.