Hydrochloric Acid → Benzophenone, 4-chloro-4'-methyl-

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Reaction Steps

175 g of 4-chlorobenzoyl chloride are added dropwise at about 70° C. to a mixture of 553 g of toluene and 140 g of AlCl3. After completion of the evolution of HCl, the reaction mixture is added to 1 1 of water, and the solid obtained is separated off and recrystallized from 20 ethanol/toluene (50:1 parts by wt). 112.7 g of 4'-chloro-4-methylbenzophenone (melting point 129° C. to 130° C.; content of 4,4,-isomer>99.5% by GCSA) are obtained. 4-(4-Chlorobenzoyl)benzoic acid (melting point 256° C. to 258° C.) is accessible from this in 95% yield by oxidation. This acid is converted into the acid chloride by phosgenation. 97.7 g of 4-(4-chlorobenzoyl)benzoyl chloride, dissolved in 250.0 g of fluorobenzene, are added dropwise at 60° C. to 85° C. to a mixture of 254.5 g of fluorobenzene and 49.0 g of AlCl3. After the evolution of gas is complete, the reaction mixture is added to 0.5 1 of water and, after distillative removal of excess fluorobenzene, the precipitate is separated off, washed until neutral and recrystallized from chlorobenzene. Yield of 1-(4chlorobenzoyl-4-(4-fluorobenzoyl)benzene: 54.0 g (melting point 211° C. to 212° C.).

Provenance & Evidence