Hexanal → 2-Hexylcyclopentanone

HRID 1090482Notes

Reaction equation

HRID 1090482 reaction equation
[C:1]1(=[O:6])[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH:7](=O)[CH2:8][CH2:9][CH2:10][CH2:11][CH3:12]>[Pd]>[CH2:7]([CH:2]1[CH2:3][CH2:4][CH2:5][C:1]1=[O:6])[CH2:8][CH2:9][CH2:10][CH2:11][CH3:12]

Participants

4

Reactant 2

HCID 6184HexanalHCID 8452Cyclopentanone2×

Product 1

HCID 1144542-HexylcyclopentanoneYield 81.9%

Reagents, catalysts & solvents 1

HCID 23938PalladiumCatalyst

Procedure

A mixture of 1008 g (12 moles) of cyclopentanone, 800 g (8 moles) of n-hexanal and 80 g of a pulverulent catalyst containing 0.5% by weight of palladium on alumina was hydrogenated in an autoclave at 140° C. and under a hydrogen pressure of 70 bar until the pressure remained constant (about 15 hours), the procedure used being similar to that described in Example 1. The catalyst was separated off and the mixture discharged from the reactor was then distilled directly. 294 g (3.5 moles) of cyclopentanone were recovered as fraction 1. 1103 g of pure 2-hexylcyclopentanone (bp. 84° C./0.35 mbar) were obtained as the main fraction; this corresponded to a selectivity of 82%, based on n-hexanal. When, as in Example 1, the molar ratio of cyclopentanone to hexanal was increased to 3:1, the selectivity increased to above 90%, as in the case of 2-heptylcyclopentanone.

Workup

  1. customwas hydrogenated in an autoclave at 140° C. and under a hydrogen
  2. custom(about 15 hours)
  3. customThe catalyst was separated off
  4. distillationwas then distilled directly

Sources & evidence

ORD record
ord-08e1a2040a0b4eb9a62e490823bdb65b
Source dataset
uspto-grants-1992_01
Patent number
US05081309

Reaction notes

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