Pentafluorobenzoic acid → Pentafluorobenzene

HRID 963782Notes

Reaction equation

HRID 963782 reaction equation
[F:1][C:2]1[C:7](C(O)=O)=[C:6]([F:11])[C:5]([F:12])=[C:4]([F:13])[C:3]=1[F:14].[OH-].[Ca+2].[OH-]>C(O)CO>[F:1][C:2]1[C:3]([F:14])=[C:4]([F:13])[C:5]([F:12])=[C:6]([F:11])[CH:7]=1

Participants

4

Reactant 2

HCID 11770Pentafluorobenzoic acidHCID 6093208Calcium Hydroxide

Product 1

HCID 9696Pentafluorobenzene

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

In a three-necked flask provided with a stirring device, a reflux condenser, and a thermometer, 13.90 g (66 m.mols) of pentafluorobenzoic acid, 40 g of ethylene glycol, and 0.82 g (11 m.mols) of calcium hydroxide were placed and heated and the ensuant reaction was continued for 6 hours, with the reaction temperature gradually lowered meanwhile from the initial level of 140° C. to the terminal level of 110° C. After the reaction was completed, pentafluorobenzene was isolated by distillation. By the distillation, pentafluorobenzene was obtained in an amount of 8.02 g (48 m.mols), i.e. in a yield of 72.8%. By gas chromatography, the product was found to have purity of not less than 99.0%. The solution remaining after the distillation could be recycled through the subsequent cycle of reaction, though the pentafluorobenzoic acid as the starting material remained in the solution.

Workup

  1. customIn a three-necked flask provided with a stirring device, a reflux condenser
  2. temperatureheated
  3. customthe ensuant reaction
  4. customlevel of 140° C.
  5. customto the terminal level of 110° C

Sources & evidence

ORD record
ord-82bc4f4b56aa41d890943b30fb9a0391
Source dataset
uspto-grants-1998_06
Patent number
US05763702

Reaction notes

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