3',4'-Difluoroacetophenone

367-11-3

75-36-5

369-33-5

Anhydrous aluminum trichloride (117 g) was slowly added to a mixed solution of 1,2-difluorobenzene (50 g) with acetyl chloride (86 g) at room temperature. The formed slurry was heated to 30°C with continuous stirring. Upon completion of the reaction, the red reaction mixture was cooled to 20 °C and subsequently slowly poured into 800 g of ice-water mixture with continued stirring for 30 min. The organic phase was separated and the aqueous phase was extracted with dichloromethane (3 x 500 ml). All organic phases were combined and washed sequentially with water (2 x 500 ml), saturated sodium bicarbonate solution (2 x 500 ml) and 15% brine (2 x 500 ml), followed by drying with anhydrous sodium sulfate. The organic phases were concentrated to remove the solvent and finally distilled under reduced pressure to collect the fractions at 95 °C/13 mmHg to give 3',4'-difluoroacetophenone (51 g).