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]+

1. concentrationconcentrated in vacuo
2. customto give the crude product which
3. customwas purified by flash column chromatography (SiO2, 70:30 hexanes/ethyl acetate)
4. customAfter removal of solvent in vacuo the free base
5. additionwas treated directly with 1.25M hydrochloric acid in methanol (25 mL)
6. concentrationThe resulting solution was concentrated in vacuo
7. washthe residue washed with ethyl acetate/hexane (5:95)

ORD record

ord-864036cd23b441b6ba836e374402f804

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09067949B2