Reaktion #8624

Reaktionsgleichung

KHSO4

2-[5-benzyloxycarbonylamino-2-(2-nitro-benzenesulfonylamino)-pentanoylamino]-3-naphthalen-2-yl-propionic acid methyl ester

dibromoethane

potassium carbonate

→

desired product

2-[3-(3-Benzyloxycarbonylamino-propyl)-4-(2-nitro-benzene-sulfonyl)-2-oxo-piperazin-1-yl]-3-naphthalen-2-yl-propionic acid methyl ester

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is cooled to room temperature
2. 2
   Extraktionthe resulting solution is extracted with ethyl acetate
3. 3
   SonstigeThe crude product is purified over silica (
4. 4
   Waschensequential elution with EtOAc/hexanes mixtures 1:2, 1:1, 100% EtOAc

Vorschrift

A mixture of 2-[5-benzyloxycarbonylamino-2-(2-nitro-benzenesulfonylamino)-pentanoylamino]-3-naphthalen-2-yl-propionic acid methyl ester, 40, (2.4 g, 3.63 mmol), dibromoethane (3.8 mL, 4.36 mmol), potassium carbonate (5.0 g, 36.3 mmol) in DMF (50 mL) is stirred at 55° C. for 18 hours. The reaction mixture is cooled to room temperature, treated with 1M KHSO4 and the resulting solution is extracted with ethyl acetate. The crude product is purified over silica (sequential elution with EtOAc/hexanes mixtures 1:2, 1:1, 100% EtOAc, then EtOAc with 5% MeOH) to afford 2.76 g of the desired product.

Quelle