Benzoic Acid → Benzoyl chloride

Participants

Reaction Steps

In the device described for example 1, 122 g of benzoic acid are reacted with phosgene after having added 0.1 g of dimethyl-chloromethyl-phosphine oxide. At the beginning the operation is carried out at a temperature just above the melting point of the benzoic acid (122°C), but while the reaction is continuing the temperature is brought down to approx. 100°C. So as to avoid sublimation, it is useful to add to the reation mixture approx. 20 g of chlorobenzene. The phosgene absorption is terminated after abt. 2 hours. After a postreaction of another hour a more then 99% crude yield of a slightly colored benzoyl chloride is obtained which, for further purification, may be submitted to further distillation under reduced pressure. The net yield is abt. 136 g corresponding to 97% theoretical yield.

Provenance & Evidence