1-Hydroxybenzotriazole → ((S)-1-Cyclohexyl-2-{(S)-2-[2-(1H-indol-3-yl)-pyridin-4-yl]-pyrrolidin-1-yl}-2-oxo-ethyl)-carbamic acid tert-butyl ester

Participants

Reaction Steps

A solution of (S)-tert-butoxycarbonylamino-cyclohexyl-acetic acid (75 mg, 0.29 mmol), HOBt (46 mg, 0.33 mmol) and HBTU (127 mg, 0.33 mmol) in DMF (5 mL) is stirred at room temperature for 30 min. Then a solution of 3-((S)-4-pyrrolidin-2-yl-pyridine-2-yl)-1H-indole (15) in DMF (5 mL) is added, followed by diisopropylethylamine (198 mg, 1.50 mmol). After stirring at room temperature for 2 h, the reaction mixture is diluted with water and extracted with EtOAc. The combined organic layers are washed with water, sat. NaHCO3, brine, dried over Na2SO4, filtered and concentrated down. The crude product is purified by flash chromatography on silica gel (EtOAc/Hexane: 5%˜40%) to give ((S)-1-Cyclohexyl-2-{(S)-2-[2-(1H-indol-3-yl)-pyridin-4-yl]-pyrrolidin-1-yl}-2-oxo-ethyl)-carbamic acid tert-butyl ester as a yellow solid (120 mg, 78%). Mass M/Z=503.34 [M+1]

Provenance & Evidence