6-bromospiro[benzo[b][1,4]oxazine-2,1'-cyclopropan]-3(4H)-one → 6-Bromo-3,4-dihydrospiro[benzo[b][1,4]oxazine-2,1'-cyclopropane]

To a stirred solution of 6-bromospiro[4H-1,4-benzoxazine-2,1′-cyclopropane]-3-one (2.6 g, 10.2 mmol) in THF (20 mL) was added 1 M solution of borane-tetrahydrofuran complex in THF (51.0 mL, 51.2 mmol). After refluxing for 6 h, the reaction mixture was cooled to room temperature and quenched by the addition of methanol. Volatiles were evaporated under reduced pressure, and the resulting residue was taken up in ethyl acetate and washed with saturated aq. sodium bicarbonate solution, water, and brine. The organic layer was dried over sodium sulfate, concentrated, and the resulting residue was purified by silica gel column chromatography to furnish 6-bromospiro[3,4-dihydro-1,4-benzoxazine-2,1′-cyclopropane] (2.3 g).

1. temperatureAfter refluxing for 6 h
2. customquenched by the addition of methanol
3. customVolatiles were evaporated under reduced pressure
4. washwashed with saturated aq. sodium bicarbonate solution, water, and brine
5. dry with materialThe organic layer was dried over sodium sulfate
6. concentrationconcentrated
7. customthe resulting residue was purified by silica gel column chromatography

ORD record

ord-9067b37f7c0243d1be232112dc272b5f

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08828951B2