4-Chloro-1,2-difluorobenzene → 2'-Chloro-4',5'-difluoroacetophenone

Participants

Reaction Steps

According to the process disclosed in EP-A2-303,291, 2-chloro-4,5-difluorobenzoic acid is prepared by acylating 1-chloro-3,4-difluorobenzene to give 2-chloro-4,5-difluoroacetophenone with a yield of 82% of theory and then oxidizing with sodium hypochlorite to 2-chloro-4,5-difluorobenzoic acid in a yield of 85.1% of theory. The total yield of this process thus only amounts to about 70% of theory, relative to the 1-chloro-3,4-difluorobenzene as the starting material. It is further a disadvantage of this process that, according to the illustrative example, the acylation must be carried out at a temperature of 120° C.

Provenance & Evidence