Synthesis
A preparation method of 2-chloro-5-nitrobenzophenone: in a four-mouth flask equipped with an electric stirrer and a thermometer, add 1.0 mol 2-chloro-5-nitrobenzoyl chloride (1.0 mol), 0.5 mol aluminum trichloride, 1 mol zinc chloride, and 3,000 ml dichloromethane, pass through nitrogen to protect, the temperature of this reaction solution was lowered to -20-15 , and then dropwise addition of 1.2 mol of benzene, the temperature of the reaction solution was controlled to be 20~-15 during the process of dropwise addition, and the temperature was kept warm and continued to stir for 2 hours after the dropwise addition was completed. After the reaction was completed, the reaction solution was slowly poured into 2000 ml of 0.5 mol/L hydrochloric acid (cooled to 0-10 ), the temperature was kept at 0-10 and stirring was continued for 5-10 min, and the aqueous phase was extracted with 500 ml of dichloroethane. The organic phase was combined, washed once with 500 ml of saturated sodium carbonate solution, then washed three times with 500 ml of water to neutral, 200 g of anhydrous magnesium sulfate was added to dry, and most of the dichloromethane was evaporated. The residual liquid was crystallized by adding 500 ml of a mixture of ethyl acetate and petroleum ether with a volume ratio of 2:1 to obtain 2-chloro-5-nitro benzophenone, and dried to obtain a product of 248.5 g with 95% yield and 99.5% purity.
