A solution of 6-fluoropyridin-2-amine (AlfaAesar, WardH, MA, 5.16 g, 46.0 mmol) in CAN (230 mL) was stirred at 0 C, then NBS (8.19 g, 46.0 mmol) was added as solvent. It was dissolved in CAN (100 mL) through the addition funnel within 30 min. After addition, the resulting green solution was stirred for another 30 min. The reaction mixture was then concentrated under reduced pressure and the residue was dissolved in DCM (20 mL) and adsorbed onto silica. Chromatographic purification (silica gel, 0-75% EtOAc in hexane solution) afforded 2-amino-5-bromo-6-fluoropyridine. White foam, yield 7.6 g, 39.8 mmol, 86%. 1HNMR (400 MHz, MeOH-d4) δ ppm 7.59 (1H, t, J=8.9 Hz), 6.32 (1H, dd, J=8.5, 1.5 Hz). m/z (ESI+) 191.0 (M+H)+.
