Reacción #86017

Ecuación de reacción

hydrochloric acid

ammonia

(R)-1-ethyl hydrogen 3-benzyloxycarbonylamino-3-ethoxycarbonylsuccinate

isobutyl chloroformate

→

title compound

Rendimiento 84.0%

(R)-diethyl 2-benzyloxycarbonylamino-2-carbamoylsuccinate

Rendimiento 84.0%

Disolventes

THF

triethylamine

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGthe mixture was stirred for 5 minutes
2. 2
   workup.STIRRINGThe reaction mixture was stirred at the same temperature for 1 hour
3. 3
   Extracciónthe mixture was extracted with ethyl acetate
4. 4
   Secadothe extract was dried over anhydrous magnesium sulfate
5. 5
   OtroThe solvent was evaporated under reduced pressure
6. 6
   Lavadothe residue was subjected to silica gel column chromatography, in which elution
7. 7
   Otrowas performed with n-hexane/ethyl acetate (1:1) for purification
8. 8
   Otrocrystallized from ethyl acetate/n-hexane

Procedimiento

A solution of (R)-1-ethyl hydrogen 3-benzyloxycarbonylamino-3-ethoxycarbonylsuccinate (1.8 g) in THF (20 mL) was added with triethylamine (0.96 mL) and isobutyl chloroformate (0.84 mL, 0.87 g) in this order at −15° C. with stirring, and the mixture was stirred for 5 minutes. A solution of 25% aqueous ammonia (0.47 mL) was dropped into the reaction mixture at the same temperature. The reaction mixture was stirred at the same temperature for 1 hour, and then poured into diluted hydrochloric acid, the mixture was extracted with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was subjected to silica gel column chromatography, in which elution was performed with n-hexane/ethyl acetate (1:1) for purification, and then crystallized from ethyl acetate/n-hexane to obtain the title compound (1.51 g, yield: 84%) as colorless crystals. Optical rotation [α]D25 was −5.7° (c 0.52, ethanol) and optical purity was 96.1% ee.

Fuente