反应详情

温度

0 °C

N-Benzyloxycarbonyl-L-tert-leucine (2.01 g, 7.6 mmol) was dissolved in DMF (20 ml), cooled in an ice bath and stirred during the addition of pentafluorophenol (2.83 g, 15.4 mmol) and EDC (2.95 9, 15.4 mmol). The mixture was stirred at 0° C. for for 1 hour then at room temperature for a further 2 hours. The solution was cooled back to 0° C., a solution of O-(2-methoxyethoxymethyl) ethanolamine in ethanol, prepared in StepG, was added and the reaction was allowed to stirovernight at room temperature. The solvent was removed under reduced pressure, the residue was dissolved in diethyl ether (50 ml), and the solution was washed successively with 1M sodium carbonate (2×30 ml),1M hydrochloric acid (2×30 ml) and brine (30 ml). The organic phase was dried over magnesium sulphate, filtered and evaporated to an oil whichwas purified by column chromatography (silica gel, gradient elution with 50-75% ethyl acetate in hexane). Yield: 1.79 g (67%). 1H--NMR; δ(CDCI3), 7.34 (5H, m), 6.54 (1H, m), 5.60 (1H, m), 5.11 (2H, m), 4.62 (2H, s), 3.93 (1H, d, J=9.3 Hz), 3.70 (4H, m), 3.57 (3H, m), 3.44(3H, s), 3.41 (1H, m) and 1.00 (9H, s).

1. temperaturecooled in an ice bath
2. waitat room temperature for a further 2 hours
3. temperatureThe solution was cooled back to 0° C.
4. additionwas added
5. customto stirovernight at room temperature
6. customThe solvent was removed under reduced pressure
7. dissolutionthe residue was dissolved in diethyl ether (50 ml)
8. washthe solution was washed successively with 1M sodium carbonate (2×30 ml),1M hydrochloric acid (2×30 ml) and brine (30 ml)
9. dry with materialThe organic phase was dried over magnesium sulphate
10. filtrationfiltered
11. customevaporated to an oil
12. customwhichwas purified by column chromatography (silica gel, gradient elution with 50-75% ethyl acetate in hexane)