Step 1: Synthesis of 4-bromo-2-(difluoromethyl)pyridine: To 4-bromopyridine-2-carbaldehyde (5.0 g, 26.88 mmol) was added diethylamino sulfur trifluoride (7.03 mL, 53.7 mmol) at room temperature and the reaction mixture was stirred for 16 hours. Upon completion of the reaction, the reaction was quenched with aqueous sodium bicarbonate (50 mL) and subsequently extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, washed with brine (2 x 50 mL), dried over anhydrous sodium sulfate, filtered and concentrated. Purification by silica gel column chromatography (100-200 mesh) using a hexane solution of 5% ethyl acetate as eluent afforded 4-bromo-2-(difluoromethyl)pyridine (3.0 g, 14.492 mmol, 54% yield).1H NMR (400 MHz, CDCl3) δ= 8.48 (d, J = 4.9 Hz, 1H), 7.82 (d, J = 1.5 Hz, 1H), 7.66-7.50 (m, 1H), 6.60 (t, 1H).LCMS: 207.9 [M + H]+.
