Reaction Steps
In a 10 mL seal tube, methyl (S)-3-methyl-1-oxo-1-((S)-2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-imidazol-2-yl)pyrrolidin-1-yl)butan-2-ylcarbamate (55 mg, 111 μmol) (Intermediate 1), benzyl (4S,7S)-4-(5-(4-bromophenyl)-1H-imidazol-2-yl)-6,10-dioxooctahydro-1H-pyridazino[1,2-a][1,2]diazepin-7-ylcarbamate (61.2 mg, 111 μmol) (Intermediate 6) and sodium bicarbonate (sat. solution, 600 μl, excess) were combined with tert-butanol (3.00 ml) to give a light brown suspension and degassed for 5 min. PdCl2(DPPF) (8.11 mg, 11.1 μmol) was added and flushed with nitrogen. It was sealed heating at 90° C. for 4 hr then diluted with EtOAc (10 ml), filtered and concentrated. The crude was purified on a silica gel column (CH2Cl2, 2%, 3%, 5%, 8% MeOH/CH2Cl2) to afford {(4S,7S)-4-[5-(4′-{2-[(S)-1-((S)-2-Methoxycarbonylamino-3-methyl-butyryl)-pyrrolidin-2-yl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-6,10-dioxo-octahydro-pyridazino[1,2-a][1,2]diazepin-7-yl}-carbamic acid benzyl ester as a light yellow solid (30 mg, 30.6%). ESI-LRMS m/e calcd for C46H51N9O7, [M+] 841. found 842 [M+H]. 1H NMR (DMSO-d6) δ: 12.23 (br. s., 1H), 11.66-11.89 (m, 1H), 7.72-7.85 (m, 5H), 7.58-7.92 (m, 4H), 7.48-7.55 (m, 1H), 7.34-7.43 (m, 3H), 7.22-7.35 (m, 1H), 7.19-7.45 (m, 3H), 5.81 (br. s., 1H), 5.77-5.86 (m, 1H), 5.01-5.13 (m, 3H), 4.92-5.21 (m, 2H), 4.47 (d, J=11.5 Hz, 1H), 4.33-4.59 (m, 1H), 4.00-4.13 (m, 1H), 3.95-4.13 (m, 1H), 3.72-3.86 (m, 1H), 3.81 (br. s., 1H), 3.54 (s, 3H), 3.45-3.64 (m, 2H), 2.82-3.00 (m, 1H), 2.79-2.96 (m, 1H), 2.08-2.35 (m, 2H), 1.76-2.05 (m, 3H), 1.50-1.67 (m, 1H), 0.80-0.95 (m, 6H).
