704-10-9

white to light yellow cryst. low melting solid

In a 1000 mL four-necked flask, 15 g (0.091 mol) of 2,4-dichlorofluorobenzene was added and cooled to 20°C. The solution was then purified with aluminum chloride. Subsequently, 200.2 g (1.5 mol) of aluminum chloride was added, the temperature was maintained between 20-30°C, and 78.5 g (1.0 mol) of acetyl chloride was slowly added dropwise, with the dropwise process being controlled to be completed in 2 to 3 hours. The reaction mixture was gradually heated to 40°C and maintained for 30 minutes, then slowly warmed to 70°C and maintained for 1~2 hours. Then, the heating was continued slowly to 110°C and the reaction was carried out at 110±2°C for 3~4 hours. After the reaction was completed, it was cooled to room temperature, 500 g of 5% hydrochloric acid solution was added and hydrolyzed at 80~90°C for 2~3 hours. After the hydrolysis product was washed to neutral, the organic phase was separated and purified by secondary distillation and recrystallization to obtain 168 g of 2',4'-dichloro-5'-fluoroacetophenone with a purity of 99.8% and a yield of 89.3%.

[1] Patent: CN102249881, 2016, B. Location in patent: Paragraph 0020; 0082-0083
[2] Tetrahedron Letters, 2009, vol. 50, # 21, p. 2525 - 2528
[3] Patent: WO2010/58421, 2010, A2. Location in patent: Page/Page column 20-21
[4] Patent: US6967205, 2005, B1. Location in patent: Page/Page column 25-26