反应详情

To a solution of Boc-His(Tos)-OH (0.81 g) in methylene chloride (10 ml) were added NMM (0.22 ml) and isobutyl chloroformate (0.26 ml) successively at -15° C., and the mixture was stirred for ten minutes. On the other hand, a solution of HCl.H-D-Trp(CHO)-Phe-OBzl (1.00 g) in DMF (20 ml) was cooled at -30° C. and thereto was added NMM (0.22 ml). This solution was added to the above mentioned mixture and stirred for two hours at -30° C. After evaporation and extraction with ethyl acetate, the organic layer was washed successively with 2% hydrochloric acid, water, 2% sodium hydrogencarbonate, water and saturated sodium chloride solution, and dried over magnesium sulfate. After evaporation, the residue was subjected to column chromatography on silica gel (100 g) and eluted with a mixture of chloroform and methanol (100:1). The fractions containing the object compound were combined and evaporated. The residue was pulverized with n-hexane, filtered, washed with n-hexane and dried to give Boc-His(Tos)-D-Trp(CHO)-Phe-OBzl (1.42 g).

1. additionThis solution was added to the
2. stirringstirred for two hours at -30° C
3. customAfter evaporation and extraction with ethyl acetate
4. washthe organic layer was washed successively with 2% hydrochloric acid, water, 2% sodium hydrogencarbonate, water and saturated sodium chloride solution
5. dry with materialdried over magnesium sulfate
6. customAfter evaporation
7. washeluted with a mixture of chloroform and methanol (100:1)
8. additionThe fractions containing the object compound
9. customevaporated
10. filtrationfiltered
11. washwashed with n-hexane
12. customdried