Carbon Dioxide → 2,6-Difluoro-4-methoxybenzoic acid

HRID 1741550Notes

Reaction equation

HRID 1741550 reaction equation
C([Li])CCC.[F:6][C:7]1[CH:8]=[C:9]([O:14][CH3:15])[CH:10]=[C:11]([F:13])[CH:12]=1.[C:16](=[O:18])=[O:17].CCOCC>C1COCC1>[F:6][C:7]1[CH:8]=[C:9]([O:14][CH3:15])[CH:10]=[C:11]([F:13])[C:12]=1[C:16]([OH:18])=[O:17]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 3283Diethyl EtherHCID 27245183,5-DifluoroanisoleHCID 178418339Butyllithium

Product 1

HCID 27782282,6-Difluoro-4-methoxybenzoic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of n-butyllithium (10.0M in hexane; 25.0 ml, 0.25 mol) was added dropwise to a stirred, cooled (-78° C.) solution of 3,5-difluoroanisole (35.9 g, 0.25 mol) in dry THF (200 ml) under dry nitrogen. The stirred mixture was maintained under these conditions for 2.5 h and then poured into a slurry of solid carbon dioxide and dry ether. The product was extracted into 10% sodium hydroxide (twice), the combined basic extracts were acidified with 36% hydrochloric acid, and the product was extracted into ether (twice), the combined ethereal extracts were washed with water and dried (MgSO4). The solvent was removed in vacuo to give a colourless solid.

Workup

  1. temperatureThe stirred mixture was maintained under these conditions for 2.5 h
  2. extractionThe product was extracted into 10% sodium hydroxide (twice), the combined basic extracts
  3. extractionthe product was extracted into ether (twice), the combined ethereal extracts
  4. washwere washed with water
  5. dry with materialdried (MgSO4)
  6. customThe solvent was removed in vacuo
  7. customto give a colourless solid

Sources & evidence

ORD record
ord-c32abbca6b1746cd937918194c33b6f4
Source dataset
uspto-grants-1994_08
Patent number
US05334327

Reaction notes

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