Triethylamine → Boc-prolylproline benzyl ester

Participants

Reaction Steps

N-t-butyloxycarbonyl-L-proline (32.29 g, 150 mmole), L-proline benzylester hydrochloride (36.26 g, 150 mmole) and HOBT (20.27 g, 150 mmole) were dissolved in methylene chloride (500 ml), and triethylamine (15.18 g, 150 mmole) and WSC hydrochloride (28.76 g, 150 mmole) were added thereto at -30° C. The mixture was stirred for 2 hours at less than 0° C., and then overnight at room temperature. The solution was washed with 5% aqueous sodium bicarbonate (400 mg, twice), 5% aqueous citric acid (400 ml, twice) and water (400 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-prolyl-L-proline benzylester (yield: 60.70 g, 100%).

Provenance & Evidence