Thionyl Chloride → 3-Chloro-2,4,5-trifluorobenzoyl chloride
Reaction equation
[F:1][C:2]1[C:10]([Cl:11])=[C:9]([F:12])[C:8]([F:13])=[C:7](Cl)[C:3]=1[C:4](O)=[O:5].S(Cl)([Cl:17])=O>>[F:1][C:2]1[C:10]([Cl:11])=[C:9]([F:12])[C:8]([F:13])=[CH:7][C:3]=1[C:4]([Cl:17])=[O:5]Participants
3
Procedure
The chlorination of the 2,4,5-trifluorobenzoic acid is carried out in the melt, under pressure and/or in a solvent, for example chlorosulphonic acid or oleum, in the presence of halogen transfer agents, for example iodine. 2,4,5-Trifluoro-3-chlorobenzoic acid is obtained in this reaction. However, since the reaction mixture still contains unchanged starting material and some 2,4,5,-trifluoro-3,6-dichlorobenzoic acid, the crude mixture is treated, without intermediate isolation, with thionyl chloride. The desired 2,4,5-trifluoro-3-chlorobenzoyl chloride is then obtained by fractional distillation. However, it is more favorable to carry out the separation by distillation of the acid fluorides.
Sources & evidence
- ORD record
- ord-03814d21227b45659a805b0580aa7f68
- Source dataset
- uspto-grants-1996_06
- Patent number
- US05530158
Reaction notes
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