Reaktion #1995800

Reaktionsgleichung

(S)-2-tert-Butoxycarbonylamino-4-methanesulfonyl-butyric acid

TOTU

piperazine-1-carboxylic acid ethyl ester

→

4-((S)-2-tert-Butoxycarbonylamino-4-methanesulfonyl-butyryl)-piperazine-1-carboxylic acid ethyl ester

Lösungsmittel

DMF

sodium hydrogen carbonate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with 400 ml of ethyl acetate
2. 2
   WaschenThe organic phase was washed with diluted saturated aqueous sodium hydrogen carbonate solution
3. 3
   Trocknendried over MgSO4
4. 4
   Sonstigethe solvents were removed under reduced pressure
5. 5
   SonstigeThe crude product was purified by chromatography on silica gel eluting with a gradient of n-heptane/ethyl acetate
6. 6
   workup.ADDITIONThe fractions containing the product
7. 7
   Sonstigethe solvent evaporated under reduced pressure

Vorschrift

To a solution of 2 g of (S)-2-tert-Butoxycarbonylamino-4-methanesulfonyl-butyric acid, 3.2 g of NEM and 2.3 g of TOTU in 10 ml of DMF, 1.2 g of piperazine-1-carboxylic acid ethyl ester was added at RT and stirred for 2 h. The reaction mixture was diluted with saturated aqueous sodium hydrogen carbonate solution and extracted with 400 ml of ethyl acetate. The organic phase was washed with diluted saturated aqueous sodium hydrogen carbonate solution and dried over MgSO4 and the solvents were removed under reduced pressure. The crude product was purified by chromatography on silica gel eluting with a gradient of n-heptane/ethyl acetate. The fractions containing the product were combined and the solvent evaporated under reduced pressure.

Quelle