864773-64-8

348-57-2

75-36-5

864773-64-8

1. in a dry reaction flask, anhydrous AlCl3 (1040 g, 7878.7 mmol) was added to 1-bromo-2,4-difluorobenzene (600 g, 3108.9 mmol) and stirred at 60 °C for 10 min. 2. acetyl chloride (366 g, 4662.4 mmol) was added slowly dropwise to the above mixture, maintaining the temperature at 60 °C for 4 hours. 3. after the dropwise addition was completed, the reaction mixture was continued to be stirred at 60 °C for 6 hours. 4. the reaction mixture was cooled to -10 °C and ice (2450 g) was added slowly, this process was controlled to be completed within 1.5 hours. 5. 12N HCl (1500mL) was added and stirred for 1 hour at room temperature. 6. EtOAc (9000mL) was added for extraction, the organic layer was separated, washed with water, dried over anhydrous Na2SO4 and filtered. 7. The organic phase was concentrated under pressure and the resulting residue was purified by silica gel column chromatography (eluent: petroleum ether/EtOAc, 50/1) to afford the target product 1-(5-bromo-2,4-difluorophenyl)ethanone (300 g, 41% yield).