Potassium Carbonate → tert-butyl (2S)-2-(5-{2-[(2S,4S)-1-[N-(methoxycarbonyl)-O-methyl-L-threonyl]-4-(methoxymethyl)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 (1-{4-(methoxymethyl)-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-methoxy-1-oxobutan-2-yl)carbamate (0.15 g, 0.22 mmol) in a mixture of DMSO (2.0 mL) and dioxane (2.0 mL) was added (S)-tert-butyl 2-(5-iodo-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (0.15 g, 0.40 mmol), tetrakis(triphenylphosphine)palladium (0.028 g, 0.024 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium (0.018 g, 0.025 mmol), and aqueous potassium carbonate (2M, 0.35 mL, 0.70 mmol). The solution was degassed with argon for 5 min and heated, with stirring, to 90° 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 preparative reverse phase HPLC (10% to 55% MeCN/water with 0.1% TFA). The desired fractions were combined and concentrated under reduced pressure to remove volatile organics. The remaining solution was basified with aqueous bicarbonate and extracted with CH2Cl2 (3×). The combined organic layers were dried over Na2SO4 and concentrated under reduced pressure to provide tert-butyl (2S)-2-(5-{2-[(2S,4S)-1-[N-(methoxycarbonyl)-O-methyl-L-threonyl]-4-(methoxymethyl)pyrrolidin-2-yl]-1,11-dihydroisochromeno[4′,3′:6,7]naphtho[1,2-d]imidazol-9-yl}-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (0.013 g, 7%).

Provenance & Evidence