反应详情

To a solution of 15 g of (S)-2-Benzyloxycarbonylamino-pentanedioic acid 5-tert-butyl ester, 20.4 g of NEM and 14.5 g of TOTU in 75 ml of DMF, 7.4 g of Piperazine-1-carboxylic acid ethyl ester 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: 20.6 g.

1. extractionextracted with 300 ml of ethyl acetate
2. washThe organic phase was washed with diluted saturated aqueous sodium hydrogen carbonate solution
3. dry with materialdried over MgSO4
4. customThe solvents were removed under reduced pressure
5. customThe crude product was purified by chromatography on silica gel eluting with n-heptane/ethyl acetate (1/1)
6. additionThe fractions containing the product
7. customthe solvent evaporated under reduced pressure