Reaktion #6176

Reaktionsgleichung

KOH

benzylmalonic acid diethyl ester

→

title compound

Ausbeute 85.0%

α-benzylacrylic acid ethyl ester

Ausbeute 85.0%

Lösungsmittel

ethanol

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated by evaporation
2. 2
   workup.ADDITION7.1 ml of water was added
3. 3
   Sonstigethe mixture was acidified in an ice bath with 6.3 ml of concentrated hydrochloric acid
4. 4
   SonstigePartitioning between water and ether
5. 5
   Sonstigethe organic phase was dried
6. 6
   workup.DISTILLATIONthe ether was distilled off
7. 7
   workup.ADDITIONThen, 12.9 ml of pyridine, 0.61 g of piperidine and 1.78 g of paraformaldehyde were added to the residue
8. 8
   TemperaturThe mixture was heated in an oil bath (130° ) for 90 minutes
9. 9
   Temperaturcooled
10. 10
    workup.ADDITION220 ml of water was added
11. 11
    Extraktionextraction
12. 12
    WaschenThe combined organic phases were washed alternatively with water, 1N HCl, water, saturated NaHCO3 solution and brine
13. 13
    TrocknenThe solution was dried (MgSO4)
14. 14
    Sonstigeevaporated

Vorschrift

A mixture of 4.0 g of KOH in 50 ml of ethanol was added at room temperature to 20 g of benzylmalonic acid diethyl ester in 40 ml of ethanol. The mixture was stirred overnight at room temperature, then concentrated by evaporation, thereafter 7.1 ml of water was added and then the mixture was acidified in an ice bath with 6.3 ml of concentrated hydrochloric acid. Partitioning between water and ether was carried out, the organic phase was dried and the ether was distilled off. Then, 12.9 ml of pyridine, 0.61 g of piperidine and 1.78 g of paraformaldehyde were added to the residue. The mixture was heated in an oil bath (130° ) for 90 minutes, cooled, 220 ml of water was added and extraction was carried out 3 times with 75 ml of n-hexane. The combined organic phases were washed alternatively with water, 1N HCl, water, saturated NaHCO3 solution and brine. The solution was dried (MgSO4) and evaporated to give the title compound as colorless oil (26 g, 85% yield) 1H NMR: 300 MHz; spectrum consistent with proposed structure.

Quelle