3-(3,4-Difluorophenyl)-2-methylprop-2-enoic acid → 3-(3,4-Difluorophenyl)-2-methylpropanoic acid

HRID 2186574Notes

Reaction equation

HRID 2186574 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:11]=[CH:12][C:13]=1[F:14])[CH:5]=[C:6]([CH3:10])[C:7]([OH:9])=[O:8]>O=[Pt]=O.CO>[F:1][C:2]1[CH:3]=[C:4]([CH:11]=[CH:12][C:13]=1[F:14])[CH2:5][CH:6]([CH3:10])[C:7]([OH:9])=[O:8]

Participants

4

Reactant 1

HCID 539805853-(3,4-Difluorophenyl)-2-methylprop-2-enoic acid

Product 1

HCID 120521423-(3,4-Difluorophenyl)-2-methylpropanoic acid

Reagents, catalysts & solvents 2

HCID 345198Adams' catalystCatalystHCID 887MethanolSolvent

Procedure

A mixture of 28 g (0.141 mol) of 3,4-difluoro-α-methylcinnamic acid, 1 g of PtO2, and 250 ml of MeOH is hydrogenated at 45 p.s.i. until the theoretical uptake is completed. The catalyst is filtered off, and the material evaporated to one-third its volume. A 15% potassium hydroxide solution (10 ml) is added, and the mixture refluxed for 30 minutes, is poured into water, and is extracted with ether (2×100 ml). The aqueous layer is acidified with concentrated HCI and ice. The oil which separates is extracted into ether, the ether solution dried over MgSO4 and evaporated to leave a clear oil which crystallizes. 3,4-difluoro-α-methylhydrocinnamic acid, M.P. 55-56° C., is isolated.

Workup

  1. filtrationThe catalyst is filtered off
  2. customthe material evaporated to one-third its volume
  3. additionA 15% potassium hydroxide solution (10 ml) is added
  4. temperaturethe mixture refluxed for 30 minutes
  5. additionis poured into water
  6. extractionis extracted with ether (2×100 ml)
  7. extractionThe oil which separates is extracted into ether
  8. dry with materialthe ether solution dried over MgSO4
  9. customevaporated
  10. customto leave a clear oil which
  11. customcrystallizes

Sources & evidence

ORD record
ord-2e6816ecf2c045b495acd3c195cfce0e
Source dataset
uspto-grants-2002_06
Patent number
US06403831B1

Reaction notes

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