반응 #159773

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6-bromospiro[4H-1,4-benzoxazine-2,1′-cyclopropane]-3-one

→

6-bromospiro[3,4-dihydro-1,4-benzoxazine-2,1′-cyclopropane]

수율 93.9%

용매

THF

THF

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후처리

1. 1
   온도After refluxing for 6 h
2. 2
   기타quenched by the addition of methanol
3. 3
   기타Volatiles were evaporated under reduced pressure
4. 4
   세척washed with saturated aq. sodium bicarbonate solution, water, and brine
5. 5
   건조The organic layer was dried over sodium sulfate
6. 6
   농축concentrated
7. 7
   기타the resulting residue was purified by silica gel column chromatography

실험 절차

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).

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