Carbon Dioxide → 3,5-Difluorobenzoic acid

HRID 1912239Notes

Reaction equation

HRID 1912239 reaction equation
[Mg].II.Br[C:5]1[CH:10]=[C:9]([F:11])[CH:8]=[C:7]([F:12])[CH:6]=1.[C:13](=[O:15])=[O:14]>Cl.C1COCC1>[F:12][C:7]1[CH:6]=[C:5]([CH:10]=[C:9]([F:11])[CH:8]=1)[C:13]([OH:15])=[O:14]

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 807IodineHCID 1363131-Bromo-3,5-difluorobenzeneHCID 5462224Magnesium

Product 1

HCID 1012653,5-Difluorobenzoic acidYield 54%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

In a reactor under an N2-atmosphere, 22.7 g (933 mmol) of magnesium flakes were added and stirred at room temperature for 3 days. Then, 80 ml of THF and an iodine flake were added, a 100 ml THF solution of 150 g (777 mmol) of 1-bromo-3,5-difluorobenzene was slowly added at room temperature, and then the mixture was refluxed for 1 hour. Next, the mixture was cooled to 10° C., slowly added with 75 g (1710 mmol) of dry ice and stirred at room temperature for 1 hour. The reaction solution was poured in 500 ml of 1N HCl(aq) and then subjected to extraction with ethyl acetate. The organic layer was collected, washed with water, dried over anhydrous magnesium sulfate, filtered to remove insoluble substance, and concentrated under a reduced pressure. The residue was washed using n-heptane to obtain 66.3 g of 3,5-difluorobenzoic acid as a white solid.

Workup

  1. temperaturethe mixture was refluxed for 1 hour
  2. temperatureNext, the mixture was cooled to 10° C.
  3. stirringstirred at room temperature for 1 hour
  4. extractionsubjected to extraction with ethyl acetate
  5. customThe organic layer was collected
  6. washwashed with water
  7. dry with materialdried over anhydrous magnesium sulfate
  8. filtrationfiltered
  9. customto remove insoluble substance
  10. concentrationconcentrated under a reduced pressure
  11. washThe residue was washed

Sources & evidence

ORD record
ord-06d0794bb6504136bbba8ae385c71962
Source dataset
uspto-grants-2013_12
Patent number
US08609208B2

Reaction notes

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