4-Chloro-1,2-difluorobenzene → 2'-Chloro-4',5'-difluoroacetophenone
Reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([F:12])=[CH:7][C:3]=1[C:4]([OH:6])=O.Cl[C:14]1C=CC(F)=C(F)C=1>>[CH3:14][C:4]([C:3]1[C:2]([Cl:1])=[CH:10][C:9]([F:11])=[C:8]([F:12])[CH:7]=1)=[O:6]Participants
3
Procedure
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.
Workup
- customis prepared