Reaktion #575835

Reaktionsgleichung

methyl N-acetyl-4-amino-3-isopropylphenylalaninate

2-(5-amino-pentanoylamino)-4-methylsulfanyl-butyric acid methyl ester

1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride

N-hydroxybenzotriazole

→

titled compound

methyl N-{5-[(N-acetyl-4-amino-3-isopropylphenylalanyl)amino]pentanoyl}methioninate

Lösungsmittel

water

triethyl amine

NaOH

methanol

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated under reduced pressure
2. 2
   workup.ADDITIONtaken up in a mixture of ethyl acetate and ethanol (3×30 mL, 1:1)
3. 3
   Trocknendried (Na2SO4)
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   workup.STIRRINGthe mixture was stirred for 16 hours
7. 7
   Extraktionextracted with ethyl acetate (2×25 mL)
8. 8
   TrocknenThe combined organics were dried (MgSO4)
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated under reduced pressure
11. 11
    Sonstigepurified on silica gel eluting with 30% methanol/ethyl acetate

Vorschrift

A mixture of methyl N-acetyl-4-amino-3-isopropylphenylalaninate in 1N NaOH (4 mL) and methanol (2 mL) was stirred for 5 hours, concentrated under reduced pressure, taken up in a mixture of ethyl acetate and ethanol (3×30 mL, 1:1), dried (Na2SO4), filtered and concentrated under reduced pressure. MS (ESI) m/z=−263 (M−H)−. To a mixture of the residue (239 mg, 0.833 mmole), 2-(5-amino-pentanoylamino)-4-methylsulfanyl-butyric acid methyl ester (298 mg, 1.0 mmole), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (240 mg, 1.25 mmole) and N-hydroxybenzotriazole (169 mg, 1.25 mmole) in DMF (3 mL) was added triethyl amine (116 μL) and the mixture was stirred for 16 hours. The mixture was diluted with water and extracted with ethyl acetate (2×25 mL) then with chloroform (2×25 mL). The combined organics were dried (MgSO4), filtered, concentrated under reduced pressure and purified on silica gel eluting with 30% methanol/ethyl acetate to provide the titled compound (316 mg). MS (ESI) m/z=+509(M+H)+, 531 (M+Na)+.

Quelle