Boron trifluoride → 1-[6-(2-Bromo-5-iodo-benzyl)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-2,2,2-trifluoro-ethanone

Participants

Reaction Steps

To a stirred solution of 6-(2-bromo-5-iodo-benzoyl)-4-(2,2,2-trifluoro-acetyl)-4H-benzo[1,4]oxazin-3-one (16.0 g, 29.252 mmol) in 1,2-dichloroethane/MeCN (1:2 mixture, 60 mL) was added triethylsilane (9.9 mL, 62.43 mmol) and borontrifluoride diethyletherate complex (4.9 mL, 38.51 mmol) simultaneously at −10° C. After stirring overnight at room temperature, the reaction was heated at 50° C. for 3 h. The reaction was quenched by the addition of aq. sodium bicarbonate (50 mL). Volatiles were evaporated under reduced pressure, and the resulting residue was extracted with ethyl acetate (2×100 mL). The organic layers were combined and washed with water and brine, then dried over sodium sulfate and concentrated to a residue which was purified by silica gel column chromatography to furnish 1-[6-(2-bromo-5-iodo-benzyl)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-2,2,2-trifluoro-ethanone (12.1 g).

Provenance & Evidence