Bromine → 2-Bromo-3,4-difluoro-1-methoxy-benzene

To a solution of 3,4-difluoroanisole (2 mL) in tetrahydrofuran (50 mL) was added n-butyllithium (2.67 mol/L n-hexane solution, 6.95 mL) at −78° C., and the mixture was stirred at the same temperature for 30 minutes. To the reaction mixture was added bromine (1.04 mL), and the mixture was stirred at −78° C. for 15 minutes. The mixture was stirred under ice-cooling for 1 hour. To the reaction mixture was added a saturated aqueous ammonium chloride solution, and the resulting mixture was extracted with diethyl ether. The extract was washed with a saturated aqueous sodium hydrogen carbonate solution and brine successively, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: n-hexane −n-hexane/ethyl acetate=9/1) to give the title compound (0.91 g)