反应详情

To a cooled solution of 2-(N-(tert.-butyloxycarbonyl)-amino)-2-methylpropan-1-ol (J. Am. Chem. Soc 113 (1991) p 8883) (4.73 g, 25 mmole), 4-dimethylamino-pyridine (0.61 g, 5 mmole) and N-benzyloxycarbonyl-L-valine (6.28 g, 25 mmole) in dichloromethane (70 ml) was added dicyclohexyl-carbodiimide (6.19 g, 30 mmole) and the mixture was stirred 2 days at room temperature. The mixture was cooled, the urethane was filtered and the solution evaporated under reduced pressure. Ethyl acetate (200 ml) was added and the organic phase was washed twice with 5% acetic acid, 5% sodium hydrogencarbonate and water. The organic phase was dried with, sodium sulfate and evaporated under reduced pressure. The product was isolated by silica gel column chromatography with hexane/ethyl acetate. Yield: 10.2 g=96%.

1. temperatureThe mixture was cooled
2. filtrationthe urethane was filtered
3. customthe solution evaporated under reduced pressure
4. additionEthyl acetate (200 ml) was added
5. washthe organic phase was washed twice with 5% acetic acid, 5% sodium hydrogencarbonate and water
6. dry with materialThe organic phase was dried with, sodium sulfate
7. customevaporated under reduced pressure
8. customThe product was isolated by silica gel column chromatography with hexane/ethyl acetate