Dimethylformamide → BOC-Thr(Bzl)-Pro-OBzl

Participants

Reaction Steps

BOC-Thr(Bzl)-OH (32.88 g, 0.15 M) was dissolved in THF (100 ml). HOBT (20.94 g, 0.155 M) and H-Pro-OBzl.HCl (37.47 g, 0.155 M) were added thereto, and DMF (200 ml) was added to prepare a solution. WSCI (28.37 ml, 0.155 M) was added dropwise during 10 minutes while cooling with a freezing mixture, then the mixture was stirred at room temperature overnight. The solvent was distilled off in vacuo. Ethyl acetate (500 ml) was added to the residue, which was then washed with 5% aqueous sodium bicarbonate (twice), saturated sodium chloride solution, 1 N HCl (twice), saturated sodium chloride (twice) and water, in that order. After drying with anhydrous sodium sulfate, the solvent was distilled off and the mixture was concentrated in vacuo to obtain oil substance [5] (57.41 g, yield: 77.1%).

Provenance & Evidence