p-Bromoacetophenone → 1-[4-[(E)-2-phenylethenyl]phenyl]ethanone

HRID 1767435Notes

Reaction equation

HRID 1767435 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([C:8](=[O:10])[CH3:9])=[CH:4][CH:3]=1.[CH2:11]=[CH:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C(N(CC)CC)C>CC([O-])=O.CC([O-])=O.[Pd+2]>[C:8]([C:5]1[CH:6]=[CH:7][C:2](/[CH:11]=[CH:12]/[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[CH:3][CH:4]=1)(=[O:10])[CH3:9]

Participants

5

Reactant 3

HCID 7466p-BromoacetophenoneHCID 7501StyreneHCID 8471Triethylamine

Product 1

HCID 15174621-[4-[(E)-2-phenylethenyl]phenyl]ethanoneYield 86.4%

Reagents, catalysts & solvents 1

HCID 167845palladium(II) acetateCatalyst

Procedure

An oven dried Schlenk flask was charged with Pd(OAc)2 (2.2 mg, 0.01 mmol, 1 mol %) and tethered ligand 2 (45.8 mg, 0.0044 mmol, 0.44 mol %). The flask was evacuated and backfilled with nitrogen and then capped with a rubber septum. Dry dimethylformamide (5 ml) was added and the mixture was stirred for 60 min at room temperature under nitrogen. 4′-Bromoacetophenone (0.199 g, 1.0 mmol), styrene (0.137 ml, 1.2 mmol), and triethylamine (0.195 ml, 1.4 mmol) were added successively. The rubber septum was replaced with a glas stopper, the flask was sealed, and the mixture was stirred at 120° C. for 20 h. After cooling to room temperature, the mixture was filtered, and the solid was washed with methyl-t-butyl ether (MTBE), water, MeOH, acetone, and once more with MTBE. The phases of the filtrate were separated and the aqueous phase was extracted with MTBE (2×30 ml). The combined organic extracts were dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by flash chromatography on silica gel (hexane/EtOAc, 10/1 to 1/1) to give E-4-acetylstilbene (0.192 g, 86%) as a white solid.

Workup

  1. customAn oven dried Schlenk flask
  2. customThe flask was evacuated
  3. customcapped with a rubber septum
  4. additionDry dimethylformamide (5 ml) was added
  5. customthe flask was sealed
  6. stirringthe mixture was stirred at 120° C. for 20 h
  7. temperatureAfter cooling to room temperature
  8. filtrationthe mixture was filtered
  9. washthe solid was washed with methyl-t-butyl ether (MTBE), water, MeOH, acetone
  10. customThe phases of the filtrate were separated
  11. extractionthe aqueous phase was extracted with MTBE (2×30 ml)
  12. dry with materialThe combined organic extracts were dried over MgSO4
  13. concentrationconcentrated under reduced pressure
  14. customThe crude product was purified by flash chromatography on silica gel (hexane/EtOAc, 10/1 to 1/1)

Sources & evidence

ORD record
ord-308df44d578049f082d6353557cd7219
Source dataset
uspto-grants-2007_06
Patent number
US07235510B2

Reaction notes

Loading…