Water → Cyclopentanone, 2-(1-hydroxypentyl)-

HRID 2308064Notes

Reaction equation

HRID 2308064 reaction equation
[OH-].[Na+].O.[CH:4](=[O:9])[CH2:5][CH2:6][CH2:7][CH3:8].[C:10]1(=[O:15])[CH2:14][CH2:13][CH2:12][CH2:11]1>CCCCCC>[OH:9][CH:4]([CH:11]1[CH2:12][CH2:13][CH2:14][C:10]1=[O:15])[CH2:5][CH2:6][CH2:7][CH3:8]

Participants

6

Reactant 4

HCID 962WaterHCID 8063PentanalHCID 8452CyclopentanoneHCID 14798Sodium Hydroxide

Product 1

HCID 162060Cyclopentanone, 2-(1-hydroxypentyl)-Yield 74.7%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Conditions

Temperature
2.5 °C

Procedure

Into a 2-litter four-neck flask fitted with a thermometer, a reflux condenser and a stirrer were added sodium hydroxide (3.2 g) and water (300 ml). Then, a mixture of pentanal (86 g) and cyclopentanone (152 g) was added dropwise with stirring at 0-5° C. over a period of 2 hours. After the addition, the reaction mixture was stirred at room temperature for 1 hour to complete the reaction. Hexane (150 ml) was added to the reaction mixture and the layers were separated from each other. The resulting organic layer was washed with an aqueous solution (200 ml) of acetic acid (1 g) and then separated. The resulting organic layer was washed with saturated brine and separated. The organic layer was evaporated on a rotary evaporator under reduced pressure to recover hexane and unreacted cyclopentanone, whereby a crude product (173 g) was obtained. The product was distilled using a Claisen distillation apparatus to obtain 127 g of 2-(1-hydroxypentyl)cyclopentanone (boiling point: 115° C./933 Pa; GC purity: 95%). The remaining 5% was 2-pentylidenecyclopentanone which is a dehydration product.

Workup

  1. customInto a 2-litter four-neck flask fitted with a thermometer, a reflux condenser and a stirrer
  2. additionwas added dropwise
  3. additionAfter the addition
  4. stirringthe reaction mixture was stirred at room temperature for 1 hour
  5. customthe reaction
  6. customthe layers were separated from each other
  7. washThe resulting organic layer was washed with an aqueous solution (200 ml) of acetic acid (1 g)
  8. customseparated
  9. washThe resulting organic layer was washed with saturated brine
  10. customseparated
  11. customThe organic layer was evaporated on a rotary evaporator under reduced pressure
  12. customto recover hexane and unreacted cyclopentanone, whereby a crude product (173 g)
  13. customwas obtained
  14. distillationThe product was distilled
  15. distillationa Claisen distillation apparatus

Sources & evidence

ORD record
ord-741ab261716049499842d2237f9b93a3
Source dataset
uspto-grants-2004_12
Patent number
US06833481B2

Reaction notes

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