(Bis(2-methoxyethyl)amino)sulfur trifluoride → 4-Bromo-1-chloro-2-(1-fluoroethyl)benzene

Bis(2-methoxyethyl)aminosulfur trifluoride (4.5 g, 20.34 mmol) was added to a stirred solution of 1-(5-bromo-2-chlorophenyl)ethanol (3.99 g, 16.95 mmol) in dichloromethane (50 mL) at 0° C. The resulting solution was stirred at 0° C. for 3 h. The reaction mixture was quenched with a 5% solution of aqueous sodium bicarbonate (100 mL) and the resulting bubbling biphasic reaction mixture was vigorously stirred at 0° C. for 15 min. The reaction mixture was diluted with water (50 mL) and extracted with dichloromethane twice. The combined organic layers were washed with 1M hydrochloric acid, dried and concentrated by rotary evaporation. The product was purified by flash chromatography on silica gel (hexanes) to yield the title compound (2.65 g, 11.16 mmol, 65.8% yield) as a clear oil: 1H NMR (CDCl3) δ 7.65 (d, 1H), 7.37 (m, 1H), 7.20 (m, 1H), 5.88 (dq, 1H), 1.61 (dd, 3H).