Reaktion #5077

Reaktionsgleichung

N-hydroxy-succinimide

Ac-Ala-OH

H-Lys(Boc)-OH

H-Lys(Boc)-OH

sodium hydroxide

hydrochloric acid

Ac-Ala-OH

triethylamine

→

Ac-Ala-Lys(Boc)-OH

Lösungsmittel

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared by the method of Anderson et al., J
2. 2
   workup.DISSOLUTIONdissolved in a solution
3. 3
   EinengenSufficient dry sodium chloride to nearly saturate the solution
4. 4
   workup.ADDITIONwas added
5. 5
   ExtraktionThe product was extracted into ethyl acetate and it
6. 6
   Waschenwas washed with 0.2N hydrochloric acid
7. 7
   Sonstigeprepared in saturated aqueous sodium chloride
8. 8
   TrocknenThe organic phase was dried over anhydrous sodium sulfate
9. 9
   Filtrationfiltered
10. 10
    SonstigeSolvent was removed by evaporation
11. 11
    SonstigeThe product was crystallized from ethyl acetate
12. 12
    Sonstigehexane to yield 7.3 g (mp 86°-89°)

Vorschrift

Ac-Ala-Lys(Boc)-OH was prepared by coupling the N-hydroxysuccinimide ester of Ac-Ala-OH, prepared by the method of Anderson et al., J. Am. Chem. Soc. 86: 1839, (1964), to H-Lys(Boc)-OH. The N-hydroxy-succinimide of Ac-Ala-OH (6.25 g, 27.4 mmoles) was dissolved in 30 mL of dioxane and was added to a solution of H-Lys(Boc)-OH (7.50 g, 30.4 mmoles) dissolved in a solution consisting of 30 mL of 1.0N sodium hydroxide and triethylamine (2.12 mL, 15.0 mmoles). The reaction mixture was stirred overnight, then acidified with hydrochloric acid. Sufficient dry sodium chloride to nearly saturate the solution was added. The product was extracted into ethyl acetate and it was washed with 0.2N hydrochloric acid prepared in saturated aqueous sodium chloride. The organic phase was dried over anhydrous sodium sulfate and filtered. Solvent was removed by evaporation. The product was crystallized from ethyl acetate:hexane to yield 7.3 g (mp 86°-89°).

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