p-Toluenesulfonic acid → 2-Methyl-2-phenylpent-4-enal

HRID 899765Notes

Reaction equation

HRID 899765 reaction equation
[C:1]1([CH:7]([CH3:10])[CH:8]=[O:9])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:11](O)[CH:12]=[CH2:13].C1(C)C=CC(S(O)(=O)=O)=CC=1.C([O-])(O)=O.[Na+]>C1C=CC=CC=1.O>[CH3:10][C:7]([C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1)([CH2:13][CH:12]=[CH2:11])[CH:8]=[O:9]

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 71462-PhenylpropanalHCID 7858Allyl AlcoholHCID 516892Sodium Bicarbonate

Product 1

HCID 911772-Methyl-2-phenylpent-4-enal

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 962WaterSolvent

Procedure

A solution of 2-phenylpropionaldehyde (9.90 mL, 74.5 mmol), allyl alcohol (20.4 mL, 300 mmol) and p-toluene sulfonic acid (0.8560 g, 4.5 mmol) in benzene (37 mL) was heated to reflux for 19 hours and a Dean-Stark trap was used to collect the water formed. The mixture was cooled to room temperature and saturated aqueous NaHCO3 (5 mL) and H2O (5 mL) were added. The phases were separated and the organic layer was washed a second time with saturated aqueous NaHCO3 (5 mL) and H2O (5 mL). The organic layer was dried (MgSO4) and concentrated under reduced pressure. A solution of the resultant yellow residue in p-xylene (150 mL) was heated to reflux for 24 hours. The solution was cooled to room temperature and concentrated under reduced pressure. The resultant aldehyde (13.0 g) was used in the next reaction without further purification.

Workup

  1. temperatureto reflux for 19 hours
  2. customto collect the water
  3. customformed
  4. customThe phases were separated
  5. washthe organic layer was washed a second time with saturated aqueous NaHCO3 (5 mL) and H2O (5 mL)
  6. dry with materialThe organic layer was dried (MgSO4)
  7. concentrationconcentrated under reduced pressure
  8. temperatureA solution of the resultant yellow residue in p-xylene (150 mL) was heated
  9. temperatureto reflux for 24 hours
  10. temperatureThe solution was cooled to room temperature
  11. concentrationconcentrated under reduced pressure
  12. customThe resultant aldehyde (13.0 g) was used in the next reaction without further purification

Sources & evidence

ORD record
ord-73615738025b40a3a794ecb275d62e9d
Source dataset
uspto-grants-2008_04
Patent number
US07354934B2

Reaction notes

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