Tetrahydrofuran → N-[(1,1-Dimethylethoxy)carbonyl]-L-alanyl-L-proline phenylmethyl ester

Participants

Reaction Conditions

Reaction Steps

THF (200 ml), H-Pro-OBzl.HCl (48.3 g, 0.2 M) and HOBT (27.0 g, 0.2 M) were added to BOC-Ala-OH (37.8 g, 0.2 M); DMF (100 ml) was added, and WSCI (36.6 ml, 0.2 M) was added dropwise at 0° C. After stirring at 0° C. for one hour and at room temperature overnight, the solvent was distilled off in vacuo. The residue was dissolved in ethyl acetate (500 ml), washed three times with 5% sodium bicarbonate solution, three times with 1 N HCl and three times with water, in that order, dried with anhydrous magnesium sulfate and concentrated in vacuo. The residue was dissolved in a small amount of benzene and charged on a column of silica gel (250 g) packed with benzene. Elution was carried out with benzene (1 l.), benzene-ethyl acetate (10:1) (1 l.) and benzene-ethyl acetate (1:1) (1 l.), and the corresponding fractions were collected and checked by TLC and concentrated in vacuo to obtain the oily substance [24] (75.55 g, yield: 100%).

Provenance & Evidence