4-Bromo-2-fluoro-N-methoxy-N-methylbenzamide → 1-(4-Bromo-2-fluorophenyl)propan-1-one

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Reaction Steps

Into a 1000-mL 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of 4-bromo-2-fluoro-N-methoxy-N-methylbenzamide (60 g, 229.01 mmol, 1.00 equiv) in tetrahydrofuran (200 mL). To the resulting mixture was then added ethylmagnesium bromide (2M) (185 mL, 1.60 equiv) dropwise with stirring at −20° C. The resulting solution was stirred for 2 h at room temperature, then cooled to 0° C. with a water/ice bath. The reaction was then quenched by the addition of NH4Cl/H2O (500 mL). The resulting solution was extracted with ethyl acetate (3×300 mL) and the organic layers combined. The resulting mixture was washed with water (1×300 mL) and brine (1×300 mL), then dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:20) to yield 1-(4-bromo-2-fluorophenyl)propan-1-one as a white solid.

Provenance & Evidence