3,4,5,6-Tetrafluorophthalic acid → 2,3,4,5-Tetrafluorobenzoic acid
Reaction equation
[F:1][C:2]1[C:3]([F:16])=[C:4]([F:15])[C:5]([F:14])=[C:6](C(O)=O)[C:7]=1[C:8]([OH:10])=[O:9].[OH-].[Ca+2].[OH-]>O>[F:1][C:2]1[C:3]([F:16])=[C:4]([F:15])[C:5]([F:14])=[CH:6][C:7]=1[C:8]([OH:10])=[O:9]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 70 °C
Procedure
In a flask of an inner volume of 1 liter, 200 g (1.0 mole) of 3,4,5,6-tetrafluorophthalonitrile, 459 g of sulfuric acid, and 391 g of water were placed and heated and stirred for reaction under reflux for 17 hours. After completion of the reaction, the reactant was cooled. The precipitate of 3,4,5,6-tetrafluorophthalic acid consequently formed was separated by filtration. The cake, on analysis, was found to contain 5.0% by weight of sulfuric acid, 2.0% by weight of ammonium sulfate, and 7.2% by weight of water in addition to 3,4,5,6-tetrafluorophthalic acid. In an autoclave having an inner volume of 1 liter, 175 g (150 g as tetrafluorophthalic acid) of a total of 263 g of the cake, 14.0 (0.189 mole) of calcium hydroxide, and 500 g of water were placed and heated and stirred for decarboxylation at 160 ° C. for 18 hours [pH 1.90 at 70° C. at the time of charging]. The reaction mixture was then treated thereafter by following the procedure of Example 1, to produce white 2,3,4,5-tetrafluorobenzoic acid. By the same calculation as in Example 1, this example was found to have produced 2,3,4,5-tetrafluorobenzoic acid in a yield of 96.4 mole % based on 3,4,5,6-tetrafluorophthalic acid.
Workup
- customwas separated by filtration
- additionin addition to 3,4,5,6-tetrafluorophthalic acid
- temperatureheated
- additionThe reaction mixture was then treated
Sources & evidence
- ORD record
- ord-65224248ce9d46058444ff9a41fb4547
- Source dataset
- uspto-grants-1988_09
- Patent number
- US04769492
Reaction notes
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