Under nitrogen protection, anhydrous dichloromethane (350 mL) and aluminum trichloride (26.6 g, 200.00 mmol) were added sequentially to a 500 mL three-necked flask. The system was a suspension. The mixture was stirred and cooled to -78 °C. A solution of 2-(4-chlorophenyl)acetyl chloride (18.9 g, 100 mmol) in dichloromethane (50 mL) was slowly added dropwise over a period of 1 hour. After the addition was complete, ethylene gas was vigorously bubbled into the solution for 10 minutes to gradually raise the reaction mixture to room temperature and stir at that temperature for 3.5 hours. The reaction progress was monitored by TLC. After confirming the completion of the reaction, the reaction solution was cooled to 0 °C and quenched with 100 mL of water. The mixture was allowed to stand and separated. The organic layer was washed sequentially with 2 M hydrochloric acid and saturated sodium bicarbonate aqueous solution, dried with anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether: ethyl acetate 20:1) to give 11.2 g of yellow solid product (yield 62%).
