Reacción #570012

Ecuación de reacción

ethylmalonic acid diethyl ester

NaOH

→

ethylmalonic acid monoethyl ester

Rendimiento 83.4%

Disolventes

ethanol

water

water

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrofitted with a mechanical stirrer, a condenser
2. 2
   Otroto go to room temperature
3. 3
   OtroBy evaporating the solvent under vacuum
4. 4
   Temperaturaheating to about 30°-35° C.
5. 5
   Otroa residue is obtained which
6. 6
   Extracciónextracted with toluene (two 130-ml portions)
7. 7
   LavadoThe toluene extracts are washed with water
8. 8
   Lavadothe aqueous phase plus the aqueous wash
9. 9
   workup.ADDITIONare brought to pH 2 by the addition of 37% HCl (50 ml)
10. 10
    Extracciónextracted with methylenechloride (four 125-ml portions)
11. 11
    Secadodried over Na2SO 4
12. 12
    Concentraciónconcentrated to dryness

Procedimiento

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.

Fuente