Phosgene → 4-Benzoylbenzoyl chloride

Participants

Reaction Steps

A total of 3.4 kg of phosgene were passed in the course of 5 hours into a solution of 4 kg of 4-hydroxybenzophenone and 190 g of benzyltrimethylammonium chloride in 11.4 kg of o-xylene. During this time, the internal temperature was increased from 95° to 1200° C. After the end of the introduction of phosgene, stirring was continued for 30 minutes at 115° C. Working up was carried out by expelling the excess phosgene with nitrogen. The salt (catalyst) precipitated toward the end of the reaction was filtered off and the solvent was distilled off. 4.9 kg (93%) of yellowish 4-chloroformylbenzophenone of melting point 67°-72° C. were obtained. This crude product containing 12.69% of Cl- (theoretical value 13.60%) was used directly for the subsequent reactions, without further purification.

Provenance & Evidence