反应详情

温度

0 °C

At 0° C. the solution of 45 mg (0.072 mmol) of HCl.Arg(Tos)-Pro-Ala-OBzl in 15 ml of anhydrous tetrahydrofuran was adjusted to pH 9, to which the pre-cold solution of 15 mg (0.079 mmol) Boc-Ala-OH, 10 mg (0.074 mmol) of 1-hydroxybenzotriazole and 16 mg (0.077 mmol) of dicyclohexylcarbodiimide in 20 ml of anhydrous tetrahydrofuran was added. The reaction mixture was stirred at 0° C. for 2 h and at room temperature for 6 h and TLC (chloroform/methanol, 30:1) indicated complete disappearance of HCl.Arg(Tos)-Pro-Ala-OBzl. The resulted precipitates of N,N-dicyclohexylurea were filtrated and the filtrate was diluted with 80 ml of ethyl acetate. The solution obtained was washed successively with saturated NaCO3 in water (50 ml×3), saturated NaCl in water (50 ml×3) and KHSO4 in water (5%, 30 ml×3). The separated ethyl acetate layer was dried with anhydrous MgSO4, and then evaporated to provide 30 mg (54%) of the title compound as a colorless powder. Mp 80–82° C., FAB-MS (m/e) 758[M+H]+.

1. customAt 0° C.
2. additionwas added
3. customThe resulted precipitates of N,N-dicyclohexylurea
4. filtrationwere filtrated
5. additionthe filtrate was diluted with 80 ml of ethyl acetate
6. customThe solution obtained
7. washwas washed successively with saturated NaCO3 in water (50 ml×3), saturated NaCl in water (50 ml×3)
8. dry with materialThe separated ethyl acetate layer was dried with anhydrous MgSO4
9. customevaporated