Reaction Steps
2-Amino-1-(4-bromo-phenyl)-ethanone HCl (2.5 g, 10 mmol) in DMF (30 mL) was treated with 1-tert-butoxycarbonylamino-cyclopropanecarboxylic acid (1.97 g, 9.8 mmol), HATU (4.02 g, 10.5 mmol), and DIPEA (5.6 mL, 31.1 mmol). The mixture was stirred for 18 hours and concentrated. The mixture was diluted with EtOAc (25 mL), and washed with saturated NaHCO3 (3 10 mL), H2O (10 mL), and brine (10 mL). The solution was dried over MgSO4 and subjected to a 80 g SiO2 COMBIFLASH column (0-100% EtOAc-hexanes gradient) to afford {1-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-cyclopropyl}-carbamic acid tert-butyl ester (3.49 g, 90%). This material (3.49 g, 8.8 mmol) in xylenes (20 mL) was treated with ammonium acetate (3.4 g, 44 mmol). The reaction was stirred at 130° C. in a sealed tube for 18 hours. The mixture was concentrated and suspended in dicholormethane (100 mL) and washed with saturated NaHCO3 (50 mL). The solution was dried over MgSO4 to afford crude {1-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-cyclopropyl}-carbamic acid tert-butyl ester, which was used without further purification: MS (ESI) m/z 379 [M+H]+. (1-{1-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-cyclopropylcarbamoyl}-2-methyl-propyl)-carbamic acid methyl ester: {1-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-cyclopropyl}-carbamic acid tert-butyl ester (3.3 g, 8.77 mmol) was treated with 4 N HCl/dioxane (40 mL) and stirred for 2 hours. The mixture was concentrated and suspended in DMF (50 mL). The mixture was treated with (S)-Moc-Val-OH (1.69 g, 9.7 mmol), HATU (3.67 g, 9.7 mmol), and N-methyl morpholone (4.8 mL, 43.9 mmol). The mixture was stirred for 18 hours and concentrated. The mixture was diluted with EtOAc (100 mL), and washed with saturated NaHCO3 (3 50 mL), H2O (50 mL), and brine (50 mL). The solution was dried over MgSO4 and subjected to a 120 g SiO2 COMBIFLASH column (0-100% EtOAc-hexanes gradient) to afford (1-{1-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-cyclopropylcarbamoyl}-2-methyl-propyl)-carbamic acid methyl ester (3.37 g, 88%): MS (ESI) m/z 436 [M+H]+. [2-Methyl-1-(1-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-cyclopropylcarbamoyl)-propyl]-carbamic acid methyl ester: (1-{1-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-cyclopropylcarbamoyl}-2-methyl-propyl)-carbamic acid methyl ester (1.38 g, 3.2 mmol) in 1,4-dioxane (25 mL) was treated with bis(pinacolato)diboron (1.69 g, 6.7 mmol), Pd(PPh3)4 (150 mg, 0.13 mmol), and KOAc (810 mg, 8.2 mmol). The mixture was stirred in a sealed tube at 80° C. for 18 hours. The mixture was filtered through a fritted glass funnel and concentrated. The mixture was then suspended in dichloromethane (10 mL) and filtered and subjected to a 120 g SiO2 COMBIFLASH column (0-100% EtOAc-hexanes gradient) to afford [2-methyl-1-(1-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-cyclopropylcarbamoyl)-propyl]-carbamic acid methyl ester (1.24 g, 81%): MS (ESI) m/z 483 [M+H]+. (1-[2-[5-(4′-{2-[1-(2-Methoxycarbonylamino-3-methyl-butyrylamino)-cyclopropyl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: [2-Methyl-1-(1-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-cyclopropylcarbamoyl)-propyl]-carbamic acid methyl ester (85 mg, 0.21 mmol) and (1-{2-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (97 mg, 0.21 mmol) in 3:1 DME/H2O (2.5 mL) were treated with Pd(PPh3)4 (10 mg, 0.0084 mmol) and K2CO3 (2 M solution, 0.42 mL, 0.84 mmol). The mixture was stirred in a sealed tube at 80° C. for 3 hours. The mixture was filtered through a fitted glass funnel and concentrated. The mixture was subjected to a reverse phase HPLC column (5-95% MeCN—H2O; 0.1% TFA modifier) to afford (1-{2-[5-(4′-{2-[1-(2-methoxycarbonylamino-3-methyl-butyrylamino)-cyclopropyl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (2.3 mg, 2%) as a white solid (TFA salt): 1H NMR (CD3OD, 300 MHz) 7.93 (s, 2H), 7.84 (m, 4H), 5.20 (m, 1H), 4.23 (d, J=7.2 Hz, 2H), 4.01 (m, 2H), 3.83 (m, 4H), 3.70 (s, 3H), 3.66 (s, 3H), 3.38 (m, 2H), 2.57 (m, 2H), 2.18 (m, 4H), 2.04 (m, 4H), 1.75 (m, 4H), 1.58 (m, 4H), 0.95 (m, 12H); MS (ESI) m/z 725 [M+H]+.
