Acetone → 4-Ethoxy-2,3-difluorobenzoic acid

HRID 1644127Notes

Reaction equation

HRID 1644127 reaction equation
CC(C)=[O:3].[CH2:5]([O:7][C:8]1[CH:15]=[CH:14][C:11]([CH2:12][OH:13])=[C:10]([F:16])[C:9]=1[F:17])[CH3:6]>[O-2].[Cr+3].[O-2].[O-2].[Cr+3].O>[CH2:5]([O:7][C:8]1[CH:15]=[CH:14][C:11]([C:12]([OH:3])=[O:13])=[C:10]([F:16])[C:9]=1[F:17])[CH3:6]

Participants

5

Reactant 2

HCID 180AcetoneHCID 467376204-Ethoxy-2,3-difluorobenzyl alcohol

Product 1

HCID 27694004-Ethoxy-2,3-difluorobenzoic acid

Reagents, catalysts & solvents 2

HCID 165971Chromium oxideCatalystHCID 962WaterSolvent

Procedure

Acetone solution (140 mL) containing 4-ethoxy-2,3-difluorobenzyl alcohol (2.1 g) was dropped into a 1.5 M sulfuring acid solution (70 mL) containing chromium (III) oxide (4.23 g), at 0° C. over one hour. The reaction mixture was stirred at room temperature for 24 hours, and added with water to thereby terminate the reaction. The organic layer was extracted three times with ethyl acetate, the organic layers were combined, and the combined organic layer was extracted twice with a 1 M aqueous sodium hydroxide solution. The organic layer was then neutralized with a 2 M hydrochloric acid, extracted three times with ethyl acetate, the organic layers were combined, and the combined organic layer was washed with saturated sodium chloride solution. The organic layer was dried over anhydrous sodium sulfate, and the solvent was vaporized off under reduced pressure, to thereby obtain 4-ethoxy-2,3-difluorobenzoic acid (7) (yield=1.8 g, yield ratio=80%) as a white solid.

Workup

  1. additionwas dropped into a 1.5 M
  2. customto thereby terminate
  3. customthe reaction
  4. extractionThe organic layer was extracted three times with ethyl acetate
  5. extractionthe combined organic layer was extracted twice with a 1 M aqueous sodium hydroxide solution
  6. extractionextracted three times with ethyl acetate
  7. washthe combined organic layer was washed with saturated sodium chloride solution
  8. dry with materialThe organic layer was dried over anhydrous sodium sulfate

Sources & evidence

ORD record
ord-97be4ce943ad402c8c7bba5ead0deaf8
Source dataset
uspto-grants-2012_02
Patent number
US08124196B2

Reaction notes

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