Hydrogen Bromide → HCID 66980994, compound

To a solution of 4-amino-3-methyl-2-(trifluoromethyl)benzonitrile (3e) (0.8 g, 4.0 mmol) in water (2 mL), cooled to 0° C., 48% aqueous HBr (10 mL, 18.5 mmol) was added followed by NaNO2 (0.33 g, 4.8 mmol) taken in water (2 mL) and stirred for 10 min. To the reaction mixture a solution of CuBr (2.7 g, 18.8 mmol) in HBr (10 mL) was added at 0° C. and slowly warmed to room temperature and then heated to 50° C. for 1 h. The reaction mixture was brought to room temperature, diluted with water (50 mL) and extracted with EtOAc (3×20 mL). The combined organic extracts were washed with water (2×20 mL), dried over Na2SO4 and concentrated under reduced pressure to give the crude compound which was purified by column chromatography to provide the bromo 3f (0.6 g, 60%) as a tan colored solid.