2-Bromo-1,4-difluorobenzene → 4-Chloro-1-(2,5-difluorophenyl)butan-1-one

Participants

Reaction Conditions

Reaction Steps

2-Bromo-1,4-difluorobenzene (53.6 g, 277.74 mmol) in THF cooled to −50° C. was added to isopropyl magnesium chloride (2M in THF)(133 mL, 266 mmol). The reaction mixture thus obtained was warmed to 0° C. and stirred for 1 h. The reaction mixture was cooled again to −50° C. 4-chloro-N-methoxy-N-methylbutanamide (40 g, 241.52 mmol) in THF (200 mL) was added dropwise to this reaction mixture with stirring and the stirring was continued at 0° C. for 1 h. The reaction mixture was quenched with saturated aqueous NH4Cl solution, extracted with ethylacetate. The organic layer collected was washed with water (500 mL) and then with brine solution, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford a crude liquid residue. The residue thus obtained was purified by column chromatography (using 60-120 silica gel and 5% EtOAc in Hexane as eluent) to afford 35 g of the title compound as a colourless liquid.

Provenance & Evidence