Reacción #1272748

Ecuación de reacción

(S)-2-Benzyloxycarbonylamino-pentanedioic acid 5-tert-butyl ester

TOTU

Piperazine-1-carboxylic acid butyl ester trifluoroacetate

→

4-((S)-2-Benzyloxycarbonylamino-4-tert-butoxycarbonyl-butyryl)-piperazine-1-carboxylic acid butyl ester

Disolventes

DMF

sodium hydrogen carbonate

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónextracted with 300 ml of ethyl acetate
2. 2
   LavadoThe organic phase was washed with diluted saturated aqueous sodium hydrogen carbonate solution
3. 3
   Secadodried over MgSO4
4. 4
   OtroThe solvents were removed under reduced pressure
5. 5
   OtroThe crude product was purified by chromatography on silica gel eluting with n-heptane/ethyl acetate (1/1)
6. 6
   workup.ADDITIONThe fractions containing the product
7. 7
   Otrothe solvent evaporated under reduced pressure

Procedimiento

To a solution of 22.4 g of (S)-2-Benzyloxycarbonylamino-pentanedioic acid 5-tert-butyl ester, 30.7 g of NEM and 21.8 g of TOTU in 75 ml of DMF, 20 g of Piperazine-1-carboxylic acid butyl ester trifluoroacetate was added at RT and stirred for 16 h. The reaction mixture was then diluted with saturated aqueous sodium hydrogen carbonate solution and then extracted with 300 ml of ethyl acetate. The organic phase was washed with diluted saturated aqueous sodium hydrogen carbonate solution and dried over MgSO4. The solvents were removed under reduced pressure. The crude product was purified by chromatography on silica gel eluting with n-heptane/ethyl acetate (1/1). The fractions containing the product were combined and the solvent evaporated under reduced pressure. Yield: 33.4 g.

Fuente