Chlorosuccinimide → 2-Amino-3-chloro-5-cyanopyridine

Into a 500 ml four-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 6.0 g (0.05 mol) of 2-amino-5-cyanopyridine, 8.3 g (0.0625 mol) of N-chlorosuccinimide and 200 g of acetonitrile were added, and the reaction was conducted at 50° C. for one hour with stirring. During the reaction, the reaction product was analyzed by liquid chromatography, whereby formation of 2-chloroamino-5-cyanopyridine was confirmed. After completion of the reaction, acetonitrile was distilled off. To separate succinimide and the desired product, 50 g of water was added to the remaining product, and the mixture was stirred. Precipitated crystals were collected by filtration, washed with 50 g of toluene and dried to obtain 6.9 g of 2-amino-3-chloro-5-cyanopyridine as slightly brown crystals (purity as measured by liquid chromatography: 98%, yield: 88%).