反应详情

48.6 g (1.0 eq) Boc-D-Glu(OBzl)-OH was dissolved in tetrahydrofuran, 24.8 g (1.5 eq) HOSu and 44.5 g (1.5 eq) DCC were added sequentially. After stirring for 5 hours in ice bath, the reaction was warmed to r.t and stirred for another 20 hours. A large number of white precipitate (DCU) precipitated, the precipitate was filtered out and washed with little tetrahydrofuran. The filtrate was stirred in ice-salt bath, and anhydrous ammonia was introduced to the solution. After 15 minutes, a large number of white precipitate precipitated, and stirred the mixture for another 1.5 hours, no more white solid precipitated out, and the reaction was completed. The precipitate was filtered and washed with tetrahydrofuran, and yellow oil was obtained after removing the tetrahydrofuran filtrate under vacuum. The yellow oil was diluted with AcOEt; and the pH of the solution was adjusted to 7 with 2N HCl aqueous solution in ice bath, and the solution was allowed to stand for 30 minutes. The AcOEt layer was separated, and successively washed with diluted hydrochloric acid, saturated sodium bicarbonate and water. After that, the AcOEt layer was dried with MgSO4 overnight. The mixture was filtered and the filtrate was evaporated to dryness under vacuum, and the residue was recrystallized with ethyl acetate-cyclo hexane to yield 34.2 g target compound with the yield of 75%, m.p.=122˜123° C., [α]=−1.8° (C=9.8 mg/mL, DMF)

1. temperaturethe reaction was warmed
2. stirringstirred for another 20 hours
3. customA large number of white precipitate (DCU) precipitated
4. filtrationthe precipitate was filtered out
5. washwashed with little tetrahydrofuran
6. stirringThe filtrate was stirred in ice-salt bath
7. additionanhydrous ammonia was introduced to the solution
8. waitAfter 15 minutes
9. customa large number of white precipitate precipitated
10. stirringstirred the mixture for another 1.5 hours
11. customno more white solid precipitated out
12. filtrationThe precipitate was filtered
13. washwashed with tetrahydrofuran
14. customyellow oil was obtained
15. customafter removing the tetrahydrofuran filtrate under vacuum
16. additionThe yellow oil was diluted with AcOEt
17. waitto stand for 30 minutes
18. customThe AcOEt layer was separated
19. washsuccessively washed with diluted hydrochloric acid, saturated sodium bicarbonate and water
20. dry with materialAfter that, the AcOEt layer was dried with MgSO4 overnight
21. filtrationThe mixture was filtered
22. customthe filtrate was evaporated to dryness under vacuum
23. customthe residue was recrystallized with ethyl acetate-cyclo hexane
24. customto yield 34.2 g target compound with the yield of 75%, m.p.=122˜123° C., [α]=−1.8° (C=9.8 mg/mL, DMF)