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]

Participants

Reaction Conditions

Reaction Steps

A solution of 1 M Borane-THF complex in THF (2.6 mL) was added to a solution of 6-bromospiro[benzo[b][1,4]oxazine-2,1′-cyclopropan]-3(4H)-one 7.21 (135 mg, 0.53 mmol) in THF (1.5 mL) at room temperature. Mixture was heated at 75° C. for 16 hours. After cooling to room temperature, reaction mixture was quenched with methanol, diluted with ethyl acetate, and washed with sat. NaHCO3 (aq). Layers were separated and aqueous was extracted with ethyl acetate. Combined organics were washed with brine, dried (Na2SO4), filtered, and concentrated under reduced pressure to yield 6-bromo-3,4-dihydrospiro[benzo[b][1,4]oxazine-2,1′-cyclopropane] 7.23 (127 mg), which was used without further purification. LCMS-ESI+ (m/z): [M+H]+ calcd for C10H11BrNO: 239.99; found: 239.96.

Provenance & Evidence