4-Acetylbiphenyl CAS 92-91-1

1. Mix 1542g (10mol) of biphenyl, 1021g (10mol) of acetic anhydride, 4-dimethylaminopyridine (15.42g) and dichloromethane (20000ml) and set aside.
2. Mix 2825g (21.2mol) of aluminum trichloride and 27000ml of dichloromethane, cool to -10°C ~ -20°C and stir evenly, keep stirring at -10°C ~ -20°C and add the above biphenyl and acetic anhydride dropwise , a mixed solution of 4-dimethylaminopyridine and dichloromethane, the dropwise addition time is 60-90 minutes, keep this temperature for 1-2 hours, slowly add hydrochloric acid solution dropwise at -10°C~-20°C, wash with water three times , dried over anhydrous magnesium sulfate, dichloromethane was distilled off under reduced pressure to obtain 1.831kg of off-white solid. The yield is 93.3%, and the melting point is 121-123°C.

Add 500mL of dichloromethane to a 1L three-necked flask, then add 100g of biphenyl and 112g of anhydrous AlCl3, then slowly add 50mL of acetyl chloride under the protection of nitrogen, and control the dropwise temperature at 0-5°C under cooling in a cold well After the dropwise addition, keep the reaction at 0-5°C for 3 hours, pour the reactant into 1500mL of ice-water mixture, separate the organic layer, extract the water layer twice with 500mL*2 of dichloromethane, combine the organic layers, and desiccant-free Dry with water Na2SO4, filter out the desiccant, and concentrate the filtrate to dryness under reduced pressure to obtain 132 g of biphenylphenone with a yield of 95.5%, m.p: 117-119°C.

Add 231g of biphenyl, 300g of aluminum chloride, and 1300ml of 4# solvent into a 2000ml reaction flask. 141g of acetyl chloride was added dropwise at 46°C, and the temperature was maintained for 3 hours after the drop was completed. Then the reaction solution was poured into 2700ml of water containing 16% flocculant, 5g of activated carbon was added, stirred for 15 minutes and then filtered. The filter cake was washed twice with 50ml@2 water, the washing liquid was combined with the original filtrate, and the water layer was separated by a separatory funnel, and the organic layer was washed twice with 500ml@2 water, and the conversion rate of biphenyl was analyzed by sampling to 100%, and then distilled Recover the 4# solvent, pour the residual material liquid into 1400ml methanol while it is hot, and cool and crystallize. After filtration, 278 g of biphenyl ethyl ketone was obtained, the mother liquor was distilled to recover methanol, the raffinate was cooled and crystallized and filtered, and the filter cake was washed with a small amount of methanol to obtain 11 g of biphenyl ethyl ketone. A total of 289g of biphenylphenone was obtained, and the total yield was 98.3%. Product melting point: 119) 120e (mp118-120e), the content of benzophenone measured by gas chromatography internal standard method is 99.8%.