p-Toluenesulfonic acid → HCID 131717380, compound

Participants

Reaction Steps

To a solution of DVal-Leu-OBzl.p-TsOH(394 mg), Boc-Ser(164 mg), HOBT.H2O(129 mg) and N-methylmorpholine (88 μl) in dichloromethane(1.6 ml) was added EDCI.HCl (161 mg) under ice cooling. The reaction mixture was stirred at room temperature for 3 h. Saturated NaHCO, (2 ml) was added and the mixture was extracted with dichloromethane(15 ml×3). The combined organic layers were dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by dry column flash chromatography on silica gel(Merck, KIESELGEL 60) with dichloromethane/methanol(50/1) for elution to give a solid. The solid was dissolved in chloroform and precipitated with hexane to give Boc-Ser-DVal-Leu-OBzl(355 mg) as a colorless powder. The tripeptide(330 mg) was dissolved in THF(3.3 ml) and 10% Pd/C(33 mg) was added. The mixture was vigorously stirred at room temperature under an atmosphere of hydrogen(under atmospheric pressure) for 2 h. The reaction mixture was filtered and the filtrate was concentrated under reduced pressure. Saturated NaCl (2 ml) was added to the residue and the mixture was extracted with EtOAc(20 ml×3). The combined organic layers were dried over MgSO4, filtered and concentrated under reduced pressure to give a solid. The solid was dissolved in chloroform and reprecipitated with hexane to give Boc-Ser-DVal-Leu(246 mg) as a colorless powder.

Provenance & Evidence