p-Bromoacetophenone → (E)-ethyl 3-(4-bromophenyl)-but-2-enoate

HRID 705480Notes

Reaction equation

HRID 705480 reaction equation
CC(C)([O-:4])C.[K+].[Br:7][C:8]1[CH:13]=[CH:12][C:11]([C:14](=O)[CH3:15])=[CH:10][CH:9]=1.[CH2:17]1[CH2:21][O:20][CH2:19][CH2:18]1>>[CH2:19]([O:20][C:21](=[O:4])/[CH:17]=[C:14](/[C:11]1[CH:12]=[CH:13][C:8]([Br:7])=[CH:9][CH:10]=1)\[CH3:15])[CH3:18]

Participants

4

Reactant 3

HCID 7466p-BromoacetophenoneHCID 8028Tetrahydrofuran3×HCID 23665647Potassium tert-butoxide

Product 1

HCID 15933615(E)-ethyl 3-(4-bromophenyl)-but-2-enoateYield 99%

Procedure

A solution of potassium tert-butoxide (10.45 g, 90.43 mmol) in THF (250 ml) was stirred under nitrogen atmosphere. A solution of triethyl phosphonoacetate (18.1 ml, 90.43 mmol) in THF (100 ml) was then added and the reaction mixture was stirred for 30 minutes at room temperature. A solution of 1-(4-Bromo-phenyl)-ethanone (6 g, 30.14 mmol) in THF (100 ml) was then added dropwise over 5 minutes. The reaction mixture was heated to reflux. After 3 hours the reaction mixture was cooled to ambient temperature and THF was removed under reduced pressure. The reaction mixture was dissolved in H2O, extracted with EtOAc, washed with H2O and brine, dried (Na2SO4) and concentrated under reduced pressure. The crude product was purified by column chromatography on silica (Hept:EtOAc 8:2) to afford the title compound (8.1 g, 99%).

Workup

  1. temperatureThe reaction mixture was heated to reflux
  2. temperatureAfter 3 hours the reaction mixture was cooled to ambient temperature
  3. customTHF was removed under reduced pressure
  4. dissolutionThe reaction mixture was dissolved in H2O
  5. extractionextracted with EtOAc
  6. washwashed with H2O and brine
  7. dry with materialdried (Na2SO4)
  8. concentrationconcentrated under reduced pressure
  9. customThe crude product was purified by column chromatography on silica (Hept:EtOAc 8:2)

Sources & evidence

ORD record
ord-7c0c8887b02d45ca9f7499c887b0435b
Source dataset
uspto-grants-2015_11
Patent number
US09174940B2

Reaction notes

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