Ethyl Acetate → 3-(2',4'-Difluoro-4-biphenylyl)butyric acid

HRID 26923Notes

Reaction equation

HRID 26923 reaction equation
C(OC(=O)C=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.Br[CH:27]([C:29]1[CH:34]=[CH:33][C:32]([C:35]2[CH:40]=[CH:39][C:38]([F:41])=[CH:37][C:36]=2[F:42])=[CH:31][CH:30]=1)[CH3:28].[C:43]([O:46]CC)(=[O:45])[CH3:44].[OH-].[K+]>CO>[F:42][C:36]1[CH:37]=[C:38]([F:41])[CH:39]=[CH:40][C:35]=1[C:32]1[CH:33]=[CH:34][C:29]([CH:27]([CH3:28])[CH2:44][C:43]([OH:46])=[O:45])=[CH:30][CH:31]=1

Participants

6

Reactant 4

HCID 8857Ethyl AcetateHCID 14797Potassium HydroxideHCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 213226214'-(1-Bromoethyl)-2,4-difluoro-1,1'-biphenyl

Product 1

HCID 213225403-(2',4'-Difluoro-4-biphenylyl)butyric acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

69.7 g. of triphenylphosphoranylideneacetic acid ethyl ester and 29.7 g. of 4-(1-bromoethyl)-2',4'-difluorobiphenyl in 300 ml. of absolute ethyl acetate are heated under reflux for 54 hours. The precipitate is filtered off and the filtrate is evaporated. Crude [1-(2',4'-difluoro-4-biphenylyl)ethyl]-triphenylphosphoranylideneacetic acid ethyl ester thus obtained is dissolved in 500 ml. of methanol to which 150 ml. of 20% potassium hydroxide solution are added and the mixture is heated under reflux for one hour. The methanol is distilled off, water is added and the reaction mixture is washed with ether and acidified with hydrochloric acid to give 3-(2',4'-difluoro-4-biphenylyl)butyric acid, m.p. 109°-110°.

Workup

  1. temperatureunder reflux for 54 hours
  2. filtrationThe precipitate is filtered off
  3. customthe filtrate is evaporated
  4. customCrude [1-(2',4'-difluoro-4-biphenylyl)ethyl]-triphenylphosphoranylideneacetic acid ethyl ester thus obtained
  5. dissolutionis dissolved in 500 ml
  6. temperaturethe mixture is heated
  7. temperatureunder reflux for one hour
  8. distillationThe methanol is distilled off
  9. additionwater is added
  10. washthe reaction mixture is washed with ether

Sources & evidence

ORD record
ord-2588f08945c54633816e98f4b48f270c
Source dataset
uspto-grants-1979_04
Patent number
US04151302

Reaction notes

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