Chloroform → O-(3-bromophenyl)hydroxylamine hydrochloride

To a solution of 2-(3-bromophenoxy)isoindoline-1,3-dione (1.85 g, 5.82 mmol) in chloroform (50 mL) and methanol (5.6 mL) under a nitrogen atmosphere was added hydrazine hydrate (0.88 mL, 17.4 mmol). The reaction mixture was stirred at ambient temperature for 15 h and concentrated in vacuo to give the crude product which was purified by flash column chromatography (SiO2, 70:30 hexanes/ethyl acetate). After removal of solvent in vacuo the free base was treated directly with 1.25M hydrochloric acid in methanol (25 mL). The resulting solution was concentrated in vacuo and the residue washed with ethyl acetate/hexane (5:95) to give O-(3-bromophenyl)hydroxylamine hydrochloride as a pale yellow solid: 1H NMR (CD3OD, 300 MHz) δ 7.43-7.36 (m, 3H), 7.18 (dt, J=7.8, 1.8 Hz, 1H); ESI MS m/z 187 [M+H]+