Synthesis
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).
References
[1] Journal of Fluorine Chemistry, 1980, vol. 15, p. 245 - 252
[2] Journal of the Indian Chemical Society, 1982, vol. 59, # 2, p. 293 - 294
[3] Heterocycles, 1981, vol. 16, # 9, p. 1545 - 1553
[4] Journal of Medicinal Chemistry, 1979, vol. 22, # 11, p. 1385 - 1389
[5] Heterocycles, 1981, vol. 16, # 1, p. 71 - 76
