1-Hydroxybenzotriazole → Boc-Val-Pro-OBzl

Participants

Reaction Steps

N-t-butyloxycarbonyl-L-valine (8.69 g, 40 mmole), L-proline benzylester hydrochloride (9.67 g, 40 mmole) and HOBt (5.40 g, 40 mmole) were dissolved in methylene chloride (150 ml), and N-methylmorcholine (4.05 g, 40 mmole) and WSC hydrochloride (7.67 g, 40 mmole) were added thereto at -30° C. The mixture was stirred for 2 hours at less than ° C., and then overnight at room temperature, washed with aqueous sodium bicarbonate (150 ml, twice), 5% aqueous citric acid (150 ml, twice) and water (150 ml) in the order given and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain N-t-butyloxycarbonyl-L-valyl-L-proline benzylester(yield: 16.32 g, 100%).

Provenance & Evidence