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 Step E (0.200 g, 0.469 mmol), N-methyl piperazine (0.062 mL, 0.563 mmol), 1-hydroxy benzotriazole (0.070 g, 0.516 mmol) and 1-[3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (0.099 g, 0.516 mmol) were combined in amine-free N,N-dimethylformamide (1.9 mL), followed by the addition of N,N-diisopropylethyl amine (0.123 mL, 0.704 mmol). The reaction was stirred at room temperature for 12 hours, then diluted with ethyl acetate and washed with water, 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 sodium sulfate, filtered and concentrated. The residue was purified by flash column chromatography on silica gel eluting with 5% methanol in chloroform to afford 0.224 g of the title compound as an oil. The oil thus obtained was dissolved in diethyl ether and diluted with hexane to afford a pale yellow solid.
