Hexanal → Methyl 2-acetyloctanoate
Reaction equation
[C:1]([O:7][CH3:8])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[CH:9](=O)[CH2:10][CH2:11][CH2:12][CH2:13][CH3:14].N1CCCCC1.[H][H]>[Pd]>[CH2:9]([CH:2]([C:3]([CH3:5])=[O:4])[C:1]([O:7][CH3:8])=[O:6])[CH2:10][CH2:11][CH2:12][CH2:13][CH3:14]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 90 °C
Procedure
The reaction mixture from the condensation of methyl acetoacetate (193.5 g) and hexanal (151.8 g) with piperidine catalysis was hydrogenated in an autoclave at 50° C. with hydrogen and Pd/C catalysis. After the end of the hydrogenation and filtering off the Pd/C catalyst, the two-phase mixture was concentrated at a pressure of 15 mbar and a temperature of 70° C. The residue (262 g) still contained 1.2 percent of methyl 2-hexenylacetoacetate. Methyl acetoacetate (3.14 g) and sodium methoxide (1.46 g of a 5.4 molar solution) were then added and this mixture was heated at 90° C. for 5 hours. At the end of this treatment, 0.39 percent of methyl 2-hexenylacetoacetate was still measured. The crude product was then distilled in a high vacuum (3 to 4 mbar) in a thin-layer evaporator. The methyl 2-hexylacetoacetate distillate (240.9 g), with a content of 97.8 percent, still contained 0.26 percent of methyl 2-hexenylacetoacetate.
Workup
- filtrationAfter the end of the hydrogenation and filtering off the Pd/C catalyst
- concentrationthe two-phase mixture was concentrated at a pressure of 15 mbar
- customa temperature of 70° C
- additionMethyl acetoacetate (3.14 g) and sodium methoxide (1.46 g of a 5.4 molar solution) were then added
- distillationThe crude product was then distilled in a high vacuum (3 to 4 mbar) in a thin-layer evaporator
Sources & evidence
- ORD record
- ord-48bf9fe988d84262b96a5981a315cd67
- Source dataset
- uspto-grants-1998_07
- Patent number
- US05786501
Reaction notes
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