3-Amino-2-bromopyridine

19755-53-4

39856-58-1

Preparation of Example S-1: 2-Bromo-3-nitropyridine (3 g, 15 mmol) was dissolved in a solvent mixture of tetrahydrofuran (15 mL) and water (5 mL), followed by the addition of iron powder (1 g, 18 mmol) and ammonium chloride (2 g, 37 mmol). The reaction mixture was stirred at 60°C to 70°C for 5 hours. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad and the filtrate was washed with brine and extracted with ethyl acetate. The organic layers were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (eluent: ethyl acetate/hexane=1:4) to afford 2-bromo-3-aminopyridine (2.6 g, 15 mmol, quantitative yield).1H-NMR (DMSO-d6) δ (ppm): 5.47 (2H, brs), 7.07-7.09 (2H, m), 7.54 (1H, dd, J=). 2.0,3.6Hz).