1-Hydroxybenzotriazole → HCID 131719302, compound

Participants

Reaction Steps

To a solution of H-DNal-DNle-OBzl (180 mg, prepared in (2)) in dichloromethane (5 ml) were added Boc-Leu-OH.H2O (180 mg), HOBT.H2O (70 mg) and EDCI.HCl (99 mg) successively under ice cooling. After being stirred at room temperature for 14 h, the mixture was diluted with ethyl acetate, washed with sat. aq. NaHCO3, 10% aq. citric acid, water and brine successively, dried over MgSO4 and evaporated in vacuo. The residue was purified by dry column flash chromatography (Merck, Kieselgel 60) with ethyl acetate/hexane=1/2 for elution to give Boc-Leu-DNal-DNle-OBzl (239 mg). A solution of the tripeptide derivative (87 mg) in 95% ethanol (10 ml) was hydrogenated over 10% Pd/C (21 mg) at an atmospheric pressure of hydrogen for 1 h. After removal of the catalyst by filtration, the filtrate was concentrated in vacuo to give Compound 16 (74 mg).

Provenance & Evidence