1004294-58-9

19798-81-3

1004294-58-9

6-Bromo-2-pyridinamine (15 g, 87 mmol) was used as a raw material, which was mixed with acetonitrile (170 mL) and N-chlorosuccinimide (14 g, 100 mmol), and heated under nitrogen protection with reflux stirring. After 18 hours of reaction, the reaction mixture was concentrated and the residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate. The organic layer was separated and washed sequentially with saturated aqueous sodium bicarbonate solution and brine, followed by drying with sodium sulfate and filtration. Silica gel (45 g) was added to the filtrate and volatiles were removed under vacuum. The residue was purified by silica gel column chromatography using a gradient elution (hexane-ethyl acetate, 6:1 to 4:1). The product obtained from the isolation was dissolved in dichloromethane, silica gel (25 g) was added and the volatiles were again removed under vacuum. Finally, the residue was further purified by silica gel column chromatography (dichloromethane-pentane, 2:1) to give 6-bromo-5-chloro-2-pyridinamine (9.8 g) as a colorless solid.