Ethyl 4-chloroacetoacetate → 4-Chloro-3-hydroxybutyric acid ethyl ester, (3R)-

Temperatur

120 °C

100 g of ethyl 4-chloro-3-oxobutyrate and 64.9 mg of {[Ru (p-cymene) I (+) TMBTP] I}, prepared in example 1, are placed under argon in a 3-liter reactor, in 1000 ml of ethyl alcohol degassed with argon; the mixture is heated at 120° C. under argon and pressurised with hydrogen at 5 bar. After 3 h, the mixture is cooled, concentrated at reduced pressure, and the residue distilled with 5 mm Hg vacuum. 91 g of ethyl (+) (R)-4-chloro-3-hydroxybutyrate are obtained with an e.e. of 97% by gas-chromatography analysis.

1. customprepared in example 1
2. customdegassed with argon
3. temperaturethe mixture is cooled
4. concentrationconcentrated at reduced pressure
5. distillationthe residue distilled with 5 mm Hg vacuum

ORD-Eintrag

ord-0a8ac851da3b43fd95dbb90f5859c41e

Quelldatensatz

uspto-grants-2003_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06566552B2