反应详情

温度

0 °C

The 2-tert-butoxycarbonylamino-pentanedioic acid 1-benzyl ester (4.06 g, 12 mmol) and TEA (5 mL, 35.87 mmol) were dissolved in THF (60 mL) and cooled to 0° C. Ethylchloroformate (3.4 mL, 35.7 mmol) was added dropwise. The mixture was stirred at 0° C. for 5 minutes and warmed to r.t. for 1 h. NaBH4 (1.88 g, 49.7 mmol) was added followed by addition of 1 drop of H2O. The reaction mixture was stirred at r.t. overnight. 4 N HCl was added at 0° C. and extracted with EtOAc (100 mL). The aqueous layer was washed with H2O (100 mL), NaOH (2×100 mL), H2O (100 mL) and brine (100 mL). The organic layer was dried with Na2SO4, filtered, and concentrated. The crude product was purified by combi-flash to give 2.89 g of 2-tert-butoxycarbonylamino-5-hydroxy-pentanoic acid benzyl ester in 75% yield.

1. temperaturewarmed to r.t. for 1 h
2. stirringThe reaction mixture was stirred at r.t. overnight
3. extractionextracted with EtOAc (100 mL)
4. washThe aqueous layer was washed with H2O (100 mL), NaOH (2×100 mL), H2O (100 mL) and brine (100 mL)
5. dry with materialThe organic layer was dried with Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product was purified by combi-flash