Azobisisobutyronitrile → 1-(Bromomethyl)-2-(difluoromethyl)benzene

To a solution of 1-(difluoromethyl)-2-methylbenzene (2.90 g, 20.4 mmol) in carbon tetrachloride (50 mL) was added N-bromosuccinimide (3.63 g, 20.4 mmol) and 2,2′-azobis(2-methylpropionitrile) (0.167 g, 1.02 mmol). The mixture was heated at reflux for 16 h. Further 2,2′-azobis(2-methylpropionitrile) (0.167 g, 1.02 mmol) was added, the mixture was heated at reflux for 4 h, allowed to cool to ambient temperature, diluted with dichloromethane (175 mL) and washed with water (2×175 mL) and saturated sodium bicarbonate (150 mL). The organic phase was dried over sodium sulfate, filtered, and concentrated in vacuo. The resultant residue was purified by column chromatography and eluted with a 0% to 10% gradient of ethyl acetate in dichloromethane to afford 1-(bromomethyl)-2-(difluoromethyl)benzene as a yellow solid: 1H NMR (300 MHz, CDCl3) δ7.58-7.56 (m, 1H), 7.43-7.37 (m, 3H), 6.95 (t, 55.2 Hz, 1H), 4.59 (s, 2H).