Reaktion #55648

Reaktionsgleichung

cyanoacetic acid

sodium hydroxide

4-methoxyphenyl acetaldehyde

glyme

→

3-[(4-methoxyphenyl)methyl]glutaric acid

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added
2. 2
   SonstigeThe glyme is evaporated in vacuo
3. 3
   workup.ADDITIONthe residue is mixed with 10% hydrochloric acid (200 ml)
4. 4
   Temperaturrefluxed for 6.0 hours
5. 5
   TemperaturAfter cooling
6. 6
   Extraktionthe mixture is extracted with ethyl acetate
7. 7
   ExtraktionThe ethyl acetate extract
8. 8
   Waschenis washed once with brine
9. 9
   Sonstigedried
10. 10
    Sonstigeevaporated
11. 11
    Waschenfor elution

Vorschrift

To a solution of cyanoacetic acid (3.57 g), in water (20 ml) is added a solution of sodium hydroxide (2.08 g) in water (20 ml). The solution is diluted with glyme (70 ml), 4-methoxyphenyl acetaldehyde (3.0 g) is added and the mixture is left at room temperature for 6.0 hours. The glyme is evaporated in vacuo, and the residue is mixed with 10% hydrochloric acid (200 ml) and refluxed for 6.0 hours. After cooling, the mixture is extracted with ethyl acetate. The ethyl acetate extract is washed once with brine, dried, evaporated and the residue subjected to chromatography on a column of silica gel using chloroform-ethyl acetate mixtures for elution to afford 2.2 g of 3-[(4-methoxyphenyl)methyl]glutaric acid. Crystallization from a benzene-ethyl acetate-hexane mixture gives a specimen having a melting point 109°-110° C.

Quelle