p-Bromoacetophenone → 1-(4-bromophenyl)-1-phenylethylene

HRID 1668700Notes

Reaction equation

HRID 1668700 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[CH:8][C:7]([Br:10])=[CH:6][CH:5]=1)=O.[C:11]1([Li])[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1>C(OCC)C>[Br:10][C:7]1[CH:8]=[CH:9][C:4]([C:2]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[CH2:1])=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 7466p-BromoacetophenoneHCID 178506676HCID 178506676, compound

Product 1

HCID 116013301-(4-bromophenyl)-1-phenylethyleneYield 84.6%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Conditions

Temperature
120 °C

Procedure

A solution of 4-bromoacetophenone (10.0 g, 50.2 mmol) in 130 mL of dry diethyl ether was added over 1.5 hours to a solution of phenyllithium (30.7 mL of 1.8 M a solution in dibutyl ether, 55.2 mmol) in 70 mL of dry diethyl ether at room temperature under an inert atmosphere. The reaction mixture was stirred while heating to reflux for 3 hours and then was examined by [C-MS which showed complete consumption of starting material. The reaction was quenched with water (500 mL), until gas evolution ceased, and 1 N HCL (31 mL). The organic layer was separated, dried over sodium sulfate and concentrated under reduced pressure. The crude product was used without any further purification. A solution of the crude (1-(4-bromo-phenyl)-1-phenyl-ethanol) and a catalytic amount of p-toluenesulfonic acid in toluene (100 mL) was heated at 120° C. for 16 h in a flask equipped with a Dean-Stark apparatus. The reaction mixture was examined by LC-MS which showed complete consumption of starting material. Solvent was evaporated under reduced pressure and the crude was purified by flash chromatography eluting with cyclohexane/ethyl acetate (100:0 to 98:2) giving 11 g of the title compound as a colorless oil (Yield: 84%)

Workup

  1. temperaturewhile heating
  2. temperatureto reflux for 3 hours
  3. customconsumption of starting material
  4. customThe reaction was quenched with water (500 mL), until gas evolution
  5. customThe organic layer was separated
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated under reduced pressure
  8. customThe crude product was used without any further purification
  9. customequipped with a Dean-Stark apparatus
  10. customconsumption of starting material
  11. customSolvent was evaporated under reduced pressure
  12. customthe crude was purified by flash chromatography
  13. washeluting with cyclohexane/ethyl acetate (100:0 to 98:2)

Sources & evidence

ORD record
ord-a89c11567df447c58cb00015e82a4b86
Source dataset
uspto-grants-2011_08
Patent number
US07989449B2

Reaction notes

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