Ammonium Chloride → 1-(3-Fluorophenyl)butan-1-one

To a solution of 3-fluoro-N-methoxy-N-methylbenzamide (130 mg, 0.71 mmol) in dry THF (2 mL) cooled to −10° C. was added propyl magnesium chloride (532 μl, 2M solution in ether, 1.1 mmol) under nitrogen. The solution was stirred at −10° C. for 1 h and at room temperature for 75 min. The solution was the poured into saturated aqueous ammonium chloride and the product extracted into ethyl acetate (3×25 mL). The organic layers were combined, washed with brine, dried (MgSO4) and concentrated to give a pale yellow oil, which was purified by chromatography using ethyl acetate-hexane (1:9) to separate the pure product (78 mg, 66%).