Methanol → Ethyl 3-(4-fluorophenyl)pentenoate

HRID 362872Notes

Reaction equation

HRID 362872 reaction equation
C([Li])C[CH2:3][CH3:4].C[OH:7].[F:8][C:9]1[CH:14]=[CH:13][C:12]([C:15](=O)[CH2:16][CH3:17])=[CH:11][CH:10]=1.[O:19]1CC[CH2:21][CH2:20]1>>[F:8][C:9]1[CH:14]=[CH:13][C:12]([C:15]([CH2:3][CH3:4])=[CH:16][C:17]([O:19][CH2:20][CH3:21])=[O:7])=[CH:11][CH:10]=1

Participants

5

Reactant 4

HCID 887MethanolHCID 8028TetrahydrofuranHCID 680044-FluoropropiophenoneHCID 178418339Butyllithium

Product 1

HCID 54034845Ethyl 3-(4-fluorophenyl)pentenoateYield 63%

Procedure

A solution of butyllithium, 1.6M in hexanes (230 ml,0.368 mol, Aldrich) was added dropwise over 0.5 hr, with rapid mechanical stirring, to a solution of triethyl phosphonoacetate (78.9 g, 0.351 mol, Aldrich) in tetrahydrofuran (800 ml, anhydrous, Aldrich) at <5° C. while blanketed with a nitrogen atmosphere. This solution was stirred for an additional 0.25 hr and cooled to -5° C. with a methanol:ice bath and a solution of 4'-fluoropropiophenone (50 g,0.328 mol, Aldrich) in tetrahydrofiran (50 ml) was then added in one portion. Stirring was continued for 18 hr without additional cooling. The solution was concentrated to a golden yellow sludge by spin evaporation in vacuo and diluted to 1000 ml with ethyl acetate. After washing with deionized water (3×100 ml) this solution was concentrated by spin evaporation in vacuo. Distillation at reduced pressure gave 45.65 g (63%) of ethyl 3-(4-fluorophenyl)pentenoate as a mixture of (E) and (Z) isomers (ratio 1:1) contaminated with 30% of triethyl phosphonoacetate as a clear liquid, b.p. 140°-146° C. at aspirator pressure;

Workup

  1. stirringStirring
  2. waitwas continued for 18 hr without additional cooling
  3. concentrationThe solution was concentrated to a golden yellow sludge by spin evaporation in vacuo
  4. additiondiluted to 1000 ml with ethyl acetate
  5. washAfter washing with deionized water (3×100 ml) this solution
  6. concentrationwas concentrated by spin evaporation in vacuo
  7. distillationDistillation at reduced pressure

Sources & evidence

ORD record
ord-8bb593bb51494217baaf86e22c0e9c2a
Source dataset
uspto-grants-1999_02
Patent number
US05872118

Reaction notes

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