1,2-Dichloroethane → 1,1-Dimethylethyl (1S,4S)-5-[N-(1H-indol-2-ylcarbonyl)-3-methyl-L-valyl]-2,5-diazabicyclo[2.2.1]heptane-2-carboxylate

Participants

Reaction Steps

To a solution of 1H-indole-2-carboxylic acid (14.6 g, 91 mmol) in CH2Cl2 (300 mL) was added 1,1-dimethylethyl (1S,4S)-5-(3-methyl-L-valyl)-2,5-diazabicyclo[2.2.1]heptane-2-carboxylate (28.1 g, 91 mmol), EDC (20.9 g, 109 mmol), HOBt (2.45 g, 18 mmol), and NMM (25.2 g, 249 mmol). The reaction mixture was stirred at room temperature for 18 h. The reaction was diluted with CH2Cl2 and washed with sat. NaHCO3 (150 mL), 1N HCl (150 mL), sat. NaHCO3 (150 mL) and brine (200 mL). The organic layer was dried over Na2SO4, filtered, and concentrated to give the crude product which was purified by column chromatography (petroleum ether/ethyl acetate, 2:1). Concentration of the desired fractions afforded the title compound (40.5 g) as a yellow solid. LCMS (m/z): 455.3 (M+H).

Provenance & Evidence