Lithium Hydroxide → α,α,3,5-Tetrafluorobenzeneacetic acid

HRID 636154Notes

Reaction equation

HRID 636154 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([C:9]([F:16])([F:15])[C:10]([O:12]CC)=[O:11])[CH:5]=[C:6]([F:8])[CH:7]=1.[OH-].[Li+]>C(O)C>[F:1][C:2]1[CH:3]=[C:4]([C:9]([F:16])([F:15])[C:10]([OH:12])=[O:11])[CH:5]=[C:6]([F:8])[CH:7]=1

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 39058314HCID 39058314, compound

Product 1

HCID 22492123α,α,3,5-Tetrafluorobenzeneacetic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethyl 3,5-difluorophenyl-α,α-difluoroacetate (from Example D24 below; 1 molar eq.) in 50% aqueous ethanol was treated with lithium hydroxide (1.5 molar eq.). The solution was stirred for 3 hours at ambient temperature then concentrated via rotary evaporation. The residue was taken up in water; a small amount of 1 N NaOH was added to make basic. The aqueous mixture was extracted with ether. The aqueous layer was acidified to pH 3 with 1 N HCl. The acid was extracted thrice with methylene chloride. The combined methylene chloride extracts were dried over Na2SO4, filtered, and concentrated.

Workup

  1. concentrationthen concentrated via rotary evaporation
  2. additiona small amount of 1 N NaOH was added
  3. extractionThe aqueous mixture was extracted with ether
  4. extractionThe acid was extracted thrice with methylene chloride
  5. dry with materialThe combined methylene chloride extracts were dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-d5adb90438f9468b9c57951754cd7984
Source dataset
uspto-grants-2001_02
Patent number
US06191166B1

Reaction notes

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