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

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Reaction Steps

To a stirred solution of 1-[6-(5-bromo-2-chloro-benzoyl)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-2,2,2-trifluoro-ethanone (36 g, 80.35 mmol) in 1,2-dichloroethane:MeCN 1:2 (180 mL) was added BF3.OEt2 (13.2 mL, 104 mmol) and Et3SiH (26.9 mL, 168.7 mmol) at 0° C. The reaction mixture was stirred overnight at room temperature then quenched by the addition of aq. NaHCO3 (˜200 mL). The resulting mixture was extracted with ethyl acetate (3×200 mL), and the combined organic layers were washed with brine (200 mL) and dried over sodium sulfate. Crude product obtained after evaporation of solvent was purified by silica gel column chromatography to furnish 1-[6-(5-bromo-2-chloro-benzyl)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-2,2,2-trifluoro-ethanone (30 g).

Provenance & Evidence