Methyl (S)-1-((2S,4S)-2-(7-bromo-1H-naphtho[1,2-d]imidazol-2-yl)-4-(methoxymethyl)pyrrolidin-1-yl)-3-methyl-1-oxobutan-2-ylcarbamate (210 mg, 0.406 mmol), methyl (S)-3-methyl-1-oxo-1-((S)-2-(7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-naphtho[1,2-d]imidazol-2-yl)pyrrolidin-1-yl)butan-2-ylcarbamate (253 mg, 0.487 mmol), Pd(PPh3)4 (47 mg, 0.0406 mmol) and K2CO3 (2M in H2O, 0.50 mL, 1.0 mmoL) were combined in DME (4 mL). The mixture was degassed with bubbling N2 for 10 min the heated to 85° C. for 15 h. After cooling, the reaction mixture was diluted with 5 mL MeOH, filtered and concentrated. The crude residue was purified by reverse phase HPLC to afford methyl {(2S)-1-[(2S,4S)-2-{2′-[(2S)-1-{(2S)-2-[(methoxycarbonyl)amino]-3-methylbutanoyl}pyrrolidin-2-yl]-1H,1′H-7,7′-binaphtho[1,2-d]imidazol-2-yl}-4-(methoxymethyl)pyrrolidin-1-yl]-3-methyl-1-oxobutan-2-yl}carbamate (140 mg, 42%). MS (ESI) m/z 831 [M+H]+.
