Benzyloxycarbonyl-L-phenylalanine → Methyl(s)-2-[(s)-2-((s)-2-benzyloxycarbonylamino-3-phenyl-propionylamino)-3-methylbutyrylamino]-3-methylbutyrate

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Reaction Steps

247 mg of Z-Phe-OH (0.825 mmol, 1 eq) were dissolved in 10 ml of dry DMF at 0° C. under argon. Then 56 mg of 1-hydroxybenzotriazole (0.5 eq), 221 mg of 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (1.4 eq) and 346 μl of Hünig's base (2.4 eq) were added, and the mixture was stirred for 30 min. 190 mg of the compound from Example 143a) were then added, and the mixture was stirred at RT for 20 h. The reaction mixture was mixed with 50 ml of saturated NaHCO3 solution and extracted with ethyl acetatet (2×30 ml). The organic phase was dried over Na2SO4, filtered and concentrated. The crude product was chromatographed on silica gel with heptane/ethyl acetate mixtures. 314 mg of the desired compound were obtained.

Provenance & Evidence