Diethyl Ether → 4,5-Difluoro-2-methoxyphenol

To a solution of 1,2-difluoro-4,5-dimethoxybenzene (5 g, 28.71 mmol, Aldrich) in methylene chloride (300 mL) cooled to 0° C. was added aluminum chloride (14.16 g, 106.2 mmol, Fluka) in several portions. At the end of the addition, the ice bath was removed and the reaction mixture was stirred at room temperature for 12 hours. Water was added to quench the reaction. Diethyl ether (200 mL) was added and the layers were separated. The aqueous layer was extracted with diethyl ether (50 mL). The combined organic layers were washed with water, brine and dried over anhydrous magnesium sulfate. The solids were filtered off and the filtrate was concentrated in vacuo. Purification of the crude residue by flash chromatography (Biotage system, 60 Å silica gel, eluting with 10% ethyl acetate in hexanes) yielded 4,5-difluoro-2-methoxy-phenol as dark oil (3.75 g, 82%).