Bromine → 2-bromo-2-(4-fluoro-phenyl)-1-(3-isopropyl-3H-benzotriazol-5-yl)-ethanone

To a stirred solution of 191 mg of 2-(4-fluoro-phenyl)-1-(3-isopropyl-3H-benzotriazol-5-yl)-ethanone in 2 mL of acetic acid was added 0.64 mL of bromine (1 M in acetic acid). The mixture was heated at 50° C. for 3 hours. The reaction mixture was cooled to 22° C. and concentrated to dryness. The residue was taken-up into ethyl acetate and washed with saturated aqueous sodium bicarbonate, brine; the organic layer was dried (sodium sulfate), filtered and the filtrate was concentrated to give 222 mg of 2-bromo-2-(4-fluoro-phenyl)-1-(3-isopropyl-3H-benzotriazol-5-yl)-ethanone as a light yellow oil. This material was used without further purification.