Reaction Steps
Following the procedure used to prepare compound 3-[2-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-pyrrolidine-1-carboxylic acid tert-butyl ester, except that 2-aza-bicyclo[2.2.1]heptane-2,3-dicarboxylic acid 2-tert-butyl ester was used instead of pyrrolidine-1,3-dicarboxylic acid 1-tert-butyl ester. 3-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester: Following the procedure used to prepare compound 3-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester, except that 342-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester was used instead of 342-(4-bromo-phenyl)-2-oxo-ethylcarbamoyl]-pyrrolidine-1-carboxylic acid tert-butyl ester. (1-{3-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: To a solution of 345-(4-bromo-phenyl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester (1.0 g, 2.4 mmol) in methanol (20 mL) was added 4.0 M solution of HCl in dioxane (4.0 mL, excess). The mixture was stirred for 3 hours at 50° C. and concentrated under reduced pressure. The residue was treated with ether to remove excess HCl. The obtained white solid was dissoved in DMF (20 mL). To the solution was added 2-methoxycarbonylamino-3-methyl-butyric acid (0.46 g, 2.6 mmol), HATU (1.0 g, 2.6 mmol) and N,N-diisopropylethylamine (2.5 mL, 14.4 mmol). The mixture was stirred at ambient for 2 hours, and then the volatile component was removed in vacuo. The residue was dissolved in ethyl acetate (200 mL), washed with 1 N NaOH solution, water and brine, dried over MgSO4, filtered and concentrated in vacuo. The obtained residue was purified by flash chromatography to provide the desired product as a white solid (1.0 g, 89%). m/z 475.1, 477.1 (M+H)+. [2-Methyl-1-(3-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-2-aza-bicyclo[2.2.1]heptane-2-carbonyl)-propyl]-carbamic acid methyl ester: Pd(PPh3)4 (73 mg, 0.06 mmol) was added to a sealed tube containing a mixture of (1-{3-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (600 mg, 1.27 mmol), bis(pinacolato)diboron (675 mg, 2.66 mmol), potassium acetate (324 mg, 3.3 mmol) and 1,4-dioxane (15 mL). The reaction mixture was flushed with nitrogen, heated at 80° C. for 16 hours, and then the volatile component was removed in vacuo. The residue was dissolved in ethyl acetate (100 mL), washed with NaHCO3 solution, water and brine, dried over Na2SO4, filtered and concentrated in vacuo. The obtained residue was purified by flash chromatography to provide the desired product as a white solid (440 mg, 66%). m/z 523.2 (M+H)+. (1-{2-[5-(4′-{2-[2-(2-Methoxycarbonylamino-3-methyl-butyryl)-2-aza-bicyclo[2.2.1]hept-3-yl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: Following the procedure used to prepare compound 2-(5-{4′-[2-(1-Boc-pyrrolidin-3-yl)-3H-imidazol-4-yl]-biphenyl-4-yl}-1H-imidazol-2-yl)-pyrrolidine-1-carboxylic acid tert-butyl ester, except that [2-methyl-1-(3-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-2-aza-bicyclo[2.2.1]heptane-2-carbonyl)-propyl]-carbamic acid methyl ester and (1-{2-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester were used instead of 2-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-pyrrolidine-1-carboxylic acid tert-butyl ester and 345-(4-bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester. 1H-NMR (300 MHz, CD3OD) δ 7.90-7.70 (m, 10H), 7.20-7.10 (m, 1H), 5.24 (t, 1H), 4.63 (s, 1H), 4.40-3.80 (m, 4H), 3.68 (s, 3H), 3.66 (s, 3H), 2.60-1.60 (m, 13H), 1.05-0.90 (m, 12H); m/z 765.2 (M+H)+. (1-{3-[5-(4′-{2-[2-(2-Methoxycarbonylamino-3-methyl-butyryl)-2-aza-bicyclo[2.2.1]hept-3-yl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: Following the procedure used to prepare compound 2-(5-{4′-[2-(1-Boc-pyrrolidin-3-yl)-3H-imidazol-4-yl}-biphenyl-4-yl]-1H-imidazol-2-yl)-pyrrolidine-1-carboxylic acid tert-butyl ester, except that [2-methyl-1-(3-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-2-aza-bicyclo[2.2.1]heptane-2-carbonyl)-propyl]-carbamic acid methyl ester and (1-{3-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-2-aza-bicyclo[2.2.1]heptane-2-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester were used instead of 2-{5-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-1H-imidazol-2-yl}-pyrrolidine-1-carboxylic acid tert-butyl ester and 3-[5-(4-bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester. 1H-NMR (300 MHz, CD3OD) δ 7.90-7.20 (m, 10H), 4.83-4.25 (m, 5H), 3.90-3.40 (m, 6H), 2.90-2.70 (m, 2H), 2.40-2.10 (m, 3H), 2.10-1.40 (m, 11H), 1.10-0.90 (m, 12H); m/z 791.3 (M+H)+.
