Fuming nitric acid (20 mL) was slowly added dropwise to a solution of 1-bromo-3,5-difluorobenzene (35.00 mL, 304 mmol) dissolved in sulfuric acid (50 mL) at 0 °C. The reaction mixture was slowly warmed to room temperature and stirred overnight. The reaction mixture was carefully poured into an ice-water mixture (600 mL) and subsequently slowly warmed to room temperature. Ethyl acetate (200 mL) and hexane (100 mL) were added and stirred until all solids were completely dissolved. The organic layer was separated, washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, filtered and concentrated in vacuum to give 2-bromo-4,6-difluoronitrobenzene as a yellow oil (57.37 g, 79% yield).GCMS analysis showed m/z = 237,239 (corresponding to Br isotope pattern).
