Reaktion #323663

Reaktionsgleichung

3-Hexadecanoyloxyoctadecanoic acid

N-hydroxysuccinimide

N,N'-Dicyclohexylcarbodiimide

L-valine

hydrochloric acid

→

N-(3-hexadecanoyloxyoctadecanoyl)-L-valine

Ausbeute 62.6%

Lösungsmittel

water

triethylamine

dioxane

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe crystallized N,N'-dicyclohexylurea was filtered off
2. 2
   Einengenthe filtrate was concentrated
3. 3
   Sonstigeto give a residue
4. 4
   workup.STIRRINGThe resulting mixture was stirred at ambient temperature overnight
5. 5
   Extraktionextracted with ethyl acetate
6. 6
   Waschenwashed with water
7. 7
   Trocknendried over magnesium sulfate
8. 8
   workup.DISTILLATIONEthyl acetate was distilled off
9. 9
   Sonstigeto give a residue which
10. 10
    Sonstigewas crystallized from petroleum ether

Vorschrift

3-Hexadecanoyloxyoctadecanoic acid (10.8 g) prepared by the method described in Preparation A-2 (5) and N-hydroxysuccinimide (2.3 g) was dissolved in dioxane (60 ml). N,N'-Dicyclohexylcarbodiimide (4.2 g) was added thereto under ice cooling. The mixture was stirred at ambient temperature over-night. The crystallized N,N'-dicyclohexylurea was filtered off and the filtrate was concentrated to give a residue. The residue was dissolved in N,N-dimethylformamide (70 ml). To this solution was added a solution of L-valine (5.85 g) and triethylamine (6.95 ml) in water (50 ml) at 0° C. The resulting mixture was stirred at ambient temperature overnight. The reaction mixture was acidified with 1N hydrochloric acid, extracted with ethyl acetate, washed with water and dried over magnesium sulfate. Ethyl acetate was distilled off to give a residue which was crystallized from petroleum ether to give crystals of N-(3-hexadecanoyloxyoctadecanoyl)-L-valine (8 g).

Quelle