Potassium Carbonate → tert-butyl(2S)-2-[5-(2-{(2S,4S)-4-ethoxy-1[N-(methoxycarbonyl)-L-valyl]pyrrolidin-2-yl}-1,11-dihydroisochromeno[4',3':6,7]naphtho[1,2-d]imidazol-9-yl)-1H-imidazol-2-yl]pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl [(2S)-1-{(2S,4S)-4-ethoxy-2-[9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,11-dihydroisochromeno[4′,3′:6,7]naphtho[1,2-d]imidazol-2-yl]pyrrolidin-1-yl}-3-methyl-1-oxobutan-2-yl]carbamate (0.41 g, 0.61 mmol) in a mixture of DME (6.1 mL) and DMF (1.0 mL) was added (S)-tert-butyl 2-(5-bromo-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (0.39 g, 1.2 mmol), tetrakis(triphenylphosphine)palladium (0.021 g, 0.018 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium (0.030 g, 0.041 mmol), and aqueous potassium carbonate (2M, 1.0 mL, 2.0 mmol). The solution was degasses with argon for 5 min and heated, with stirring, to 85° C. for 6 h. The solution was cooled to room temperature and diluted with EtOAc. The organic layer was washed with water and brine. The aqueous layers were back extracted with EtOAc (3×). The combined organic layers were dried over Na2SO4 and concentrated under reduced pressure. The crude residue was purified by silica column chromatography (20% to 100% EtOAc (w/5% MeOH)/Hexanes to 80% MeOH/EtOAc) to afford tert-butyl (2S)-2-[5-(2-{(2S,4S)-4-ethoxy-1-[N-(methoxycarbonyl)-L-valyl]pyrrolidin-2-yl}-1,11-dihydroisochromeno[4′,3′:6,7]naphtho[1,2-d]imidazol-9-yl)-1H-imidazol-2-yl]pyrrolidine-1-carboxylate (0.16 g, 33%).

Provenance & Evidence