Toluene → 4-benzyl-2-cyclohexen-1-one

HRID 1737169Notes

Reaction equation

HRID 1737169 reaction equation
N1[CH2:6][CH2:5][O:4]CC1.[C:7]1([CH3:13])[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[C:14]1(CCC=O)[CH:19]=CC=[CH:16][CH:15]=1.[OH-].[K+]>CO.C(O)(=O)C>[CH2:13]([CH:15]1[CH2:16][CH2:6][C:5](=[O:4])[CH:19]=[CH:14]1)[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

7

Reactant 4

HCID 1140TolueneHCID 7707BenzenepropanalHCID 8083Morpholine2×HCID 14797Potassium Hydroxide

Product 1

HCID 117692464-benzyl-2-cyclohexen-1-oneYield 30%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 887MethanolSolvent2×

Procedure

A 1-liter four-necked flask equipped with a Dean-Stark trap and a thermometer was charged with 71 g of morpholine and 400 ml of toluene, and 100 g of 3-phenylpropionaldehyde were added dropwise thereto while chilling with ice water, followed by azeotropic dehydration for 1 hour. After cooling the reaction mixture, excess morpholine was distilled off with toluene. The residue was dissolved in 400 ml of toluene. In a 1-liter four-necked flask equipped with a thermometer and a condenser, 70 g of methyl vinyl ketone were added dropwise under reflux to the solution over 1 hour. After aging under reflux for 1 hour, the reaction mixture was cooled, and 10% sulfuric acid was added dropwise to the reaction mixture until the pH of the reaction mixture reached 3. The thus-acidified reaction mixture was then stirred at room temperature for 1.5 hours. After separating the resulting lower water layer, the residual organic layer was neutralized, washed with water, dried and concentrated, thereby obtaining 137 g of a crude product. Dissolved in 500 ml of methanol were 137 g of the crude product, and 4 ml of 4.5 mol/liter aqueous KOH were added dropwise to the solution at room temperature, followed by stirring for 3 hours at the same temperature. After neutralizing the resultant mixture with acetic acid, methanol was distilled off. After the residue was charged into a 1-liter four-necked flask equipped with a Dean-Stark trap and a thermometer to dissolve it in 500 ml of toluene, 2 g of p-toluenesulfonic acid were added to the solution, followed by azeotropic dehydration for 3 hours. After cooling, the residue was neutralized and washed with water, and the resultant organic layer was dried and concentrated, thereby obtaining 119 g of a crude product. This product was purified by column chromatography to obtain 41 g (yield: 30%) of 4-benzyl-2-cyclohexen-1-one.

Workup

  1. customA 1-liter four-necked flask equipped with a Dean-Stark trap
  2. additionwere added dropwise
  3. distillationwas distilled off with toluene
  4. dissolutionThe residue was dissolved in 400 ml of toluene
  5. customIn a 1-liter four-necked flask equipped with a thermometer and a condenser, 70 g of methyl vinyl ketone
  6. additionwere added dropwise
  7. temperatureunder reflux to the solution over 1 hour
  8. temperatureunder reflux for 1 hour
  9. temperaturethe reaction mixture was cooled
  10. addition10% sulfuric acid was added dropwise to the reaction mixture until the pH of the reaction mixture
  11. customAfter separating the resulting lower water layer
  12. washwashed with water
  13. customdried
  14. concentrationconcentrated
  15. customobtaining 137 g of a crude product
  16. additionwere added dropwise to the solution at room temperature
  17. stirringby stirring for 3 hours at the same temperature
  18. distillationwas distilled off
  19. additionAfter the residue was charged into a 1-liter four-necked flask
  20. customequipped with a Dean-Stark trap
  21. dissolutiona thermometer to dissolve it in 500 ml of toluene
  22. addition2 g of p-toluenesulfonic acid were added to the solution
  23. waitfollowed by azeotropic dehydration for 3 hours
  24. temperatureAfter cooling
  25. washwashed with water
  26. customthe resultant organic layer was dried
  27. concentrationconcentrated
  28. customobtaining 119 g of a crude product
  29. customThis product was purified by column chromatography

Sources & evidence

ORD record
ord-c94b7c51ed5648d4acba3ec777f883d2
Source dataset
uspto-grants-1999_10
Patent number
US05962403

Reaction notes

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