1-Hydroxybenzotriazole → (2S)-2-{[10-(4-Cyclohex-1-en-1-yl-3-methyl-benzoyl)-10,11-dihydro-5H-pyrrolo [2,1-c][1,4] benzodiazepine-3-carbonyl]-amino}-3-(4-hydroxy-phenyl)-propionic acid ethyl ester

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Reaction Steps

10-(4-Cyclohex-1-en-1-yl-3-methyl-benzoyl)-10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-3-carboxylic acid of Example 5, Step E (0.240 g, 0.563 mmol), L-tyrosine ethyl ester hydrochloride (0.157 g, 0.676 mmol), 1-hydroxy benzotriazole (0.084 g, 0.619 mmol) and 1-[3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (0.119 g, 0.619 mmol) were combined in amine-free N,N-dimethylformamide (2.25 mL), followed by the addition of N,N-diisopropylethylamine (0.294 mL, 1.69 mmol). The reaction was stirred at room temperature for 36 hours, then diluted with ethyl acetate and washed with water, 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, and brine. The combined aqueous washings were saturated with sodium chloride and extracted with ethyl acetate. The combined organic phases were dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by flash column chromatography on silica gel eluting with 50% ethyl acetate in hexane, followed by precipitation from diethyl ether with petroleum ether, to afford 0.207 g of the title compound as a white solid.

Provenance & Evidence