Reaktion #86031

Reaktionsgleichung

hydrochloric acid

ammonia

(R)-1-benzyl hydrogen 3-t-butyloxycarbonylamino-3-ethoxycarbonylsuccinate

isobutyl chloroformate

→

title compound

Ausbeute 55.0%

(R)-1-benzyl ethyl 3-t-butyloxycarbonylamino-3-carbamoylsuccinate

Ausbeute 55.0%

Lösungsmittel

THF

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred for 30 minutes
2. 2
   workup.STIRRINGThe reaction mixture was stirred at the same temperature for 30 minutes
3. 3
   Extraktionthe mixture was extracted with ethyl acetate
4. 4
   Trocknenthe extract was dried over anhydrous magnesium sulfate
5. 5
   SonstigeThe solvent was evaporated under reduced pressure
6. 6
   Waschenthe residue was subjected to silica gel column chromatography, in which elution
7. 7
   Sonstigewas performed with n-hexane/ethyl acetate (1:1) for purification
8. 8
   Sonstigecrystallized from ethyl acetate/n-hexane

Vorschrift

A solution of (R)-1-benzyl hydrogen 3-t-butyloxycarbonylamino-3-ethoxycarbonylsuccinate (1.0 g) obtained in Example 19 in THF (20 mL) was added with triethylamine (0.62 mL) and isobutyl chloroformate (0.55 mL, 0.57 g) in this order at −15° C. with stirring, and the mixture was stirred for 30 minutes. A solution of 25% aqueous ammonia (0.30 mL) was dropped into the reaction mixture at the same temperature. The reaction mixture was stirred at the same temperature for 30 minutes, and then poured into diluted hydrochloric acid, the mixture was extracted with ethyl acetate, and then 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 (0.60 g, yield: 55%) as colorless crystals. Optical rotation [α]D25 was +1.28° (c 0.50, ethanol).

Quelle