Reaktion #570012

Reaktionsgleichung

ethylmalonic acid diethyl ester

NaOH

→

ethylmalonic acid monoethyl ester

Ausbeute 83.4%

Lösungsmittel

ethanol

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefitted with a mechanical stirrer, a condenser
2. 2
   Sonstigeto go to room temperature
3. 3
   SonstigeBy evaporating the solvent under vacuum
4. 4
   Temperaturheating to about 30°-35° C.
5. 5
   Sonstigea residue is obtained which
6. 6
   Extraktionextracted with toluene (two 130-ml portions)
7. 7
   WaschenThe toluene extracts are washed with water
8. 8
   Waschenthe aqueous phase plus the aqueous wash
9. 9
   workup.ADDITIONare brought to pH 2 by the addition of 37% HCl (50 ml)
10. 10
    Extraktionextracted with methylenechloride (four 125-ml portions)
11. 11
    Trocknendried over Na2SO 4
12. 12
    Einengenconcentrated to dryness

Vorschrift

A solution of ethylmalonic acid diethyl ester (123.6 g) in 95% ethanol (650 ml) is placed in a 1-l four-necked flask fitted with a mechanical stirrer, a condenser, a thermometer and a dropping funnel, and cooled to about 10° C. A solution of NaOH (26.8 g) in water (33 ml) is added dropwise into the above solution over a period of 15 minutes. The mixture is allowed to go to room temperature and stirring is continued for about 1 hour until a neutral pH is reached. By evaporating the solvent under vacuum and heating to about 30°-35° C., a residue is obtained which is taken up with water (400 ml) and extracted with toluene (two 130-ml portions). The toluene extracts are washed with water and the aqueous phase plus the aqueous wash are brought to pH 2 by the addition of 37% HCl (50 ml) and extracted with methylenechloride (four 125-ml portions). The methylene chloride extracts are combined, dried over Na2SO 4 and concentrated to dryness yielding ethylmalonic acid monoethyl ester (87.7 g) as a thick oil.

Quelle