Triethylamine → 3-(4-Benzyloxy-phenyl)-2-(2-methanesulfonylamino-4-methyl-pentanoylamino)-propionic acid tert-butyl ester

Participants

Reaction Steps

A solution of the product from Example AI ([S-(R*,R*)]-2-{2-amino-4-methyl-pentanoylamino}-3-(4-benzyloxy-phenyl)-propionic acid tert-butyl ester) (0.25 g, 1.7 mmol) and triethylamine (0.5 mL) in CH2Cl2 (10 mL) was treated with methansulfonyl chloride (0.25 mL). The resulting solution was stirred overnight at room temperature. The reaction mixture was treated with ethyl acetate (100 mL) and washed sequentially with aqueous 1N HCl solution (3×20 mL), saturated aqueous NaHCO3 solution (3×20 mL), and brine (3×20 mL). The organic phase was dried (MgSO4), filtered, and concentrated. The residue was purified by chromatography (silica gel, 1:1 ethyl acetate/heptane) to give the title compound as a pale peach powder (0.15 g, 51%), mp=83-84° C.

Provenance & Evidence