Chlorosuccinimide → 4-Bromo-5-chloropyridin-2-amine

To a solution of 4-bromopyridin-2-amine (500 mg, 2.89 mmol) in N,N-dimethylformamide (5 mL) was added N-chlorosuccinimide (463 mg, 3.47 mmol) and the mixture was stirred at room temperature for 12 hours. The mixture was filtered through diatomaceous earth and concentrated and the residue was dissolved in ethyl acetate. The solution was washed with water and brine, dried over anhydrous sodium sulfate, filtered, and concentrated to afford the crude title compound. Purification by column chromatography (silica gel, 30% ethyl acetate in hexane) afforded the title compound.