Triethylamine → 2(S)-{2(R)-[(Azepane-1-carbonyl)-amino]-4-methyl-pentanoylamino}-3-(4-benzyloxy-phenyl)-propionic acid tert-butyl ester

Participants

Reaction Steps

A solution of the product from Example AA ((R)-2-[(azepane-1-carbonyl)-amino]-4-methyl-pentanoic acid) (1.0 g, 3.9 mmol) and triethylamine (1.1 mL, 7.8 mmol) in acetonitrile (15 mL) was treated with HBTU (1.54 g, 4.06 mmol). The resulting solution was treated with the product from Example A ((S)-2-amino-3-(4-benzyloxy-phenyl)-propionic acid tert-butyl ester) (1.33 g, 4.06 mmol), and the resulting solution was stirred at room temperature for 30 minutes and allowed to stand overnight. The reaction mixture was concentrated and the residue dissolved in ethyl acetate (100 mL) and washed sequentially with 0.6 M aqueous NaHCO3 solution, saturated aqueous NaCl solution, and water. The organic phase was dried over MgSO4 and activated charcoal, filtered, and concentrated. The residue was purified by chromatography (silica gel, 25% ethyl acetate/hexane) to give the title compound as a white solid (1.9 g, 86%), mp=64-66° C.

Provenance & Evidence