Reaction Steps
To a solution of 4-(5-chloropyridin-3-yl)-N′-hydroxy-2-[(2S,4R)-4-methoxy-2-(propan-2-yl)pyrrolidin-1-yl]-3-[(trans-4-methylcyclohexyl)methyl]-3H-imidazo[4,5-c]pyridine-6-carboximidamide (79 mg, 0.146 mmol) and 1,1′-carbonyldiimidazole (26.1 mg, 0.161 mmol) dissolved in acetonitrile (1 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (0.087 mL, 0.585 mmol). The reaction mixture was stirred at room temperature for 1 hour. The reaction was washed with water and extracted with dichloromethane. The organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (0-10% methanol/dichloromethane, and then 0-100% ethyl acetate/hexanes, linear gradient) to afford 3-{4-(5-chloropyridin-3-yl)-2-[(2S,4R)-4-methoxy-2-(propan-2-yl)pyrrolidin-1-yl]-3-[(trans-4-methylcyclohexyl)methyl]-3H-imidazo[4,5-c]pyridin-6-yl}-1,2,4-oxadiazol-5(4H)-one. MS ESI calc'd. for C29H36ClN7O3 [M+H]+ 566. found 566. 1H NMR (500 MHz, DMSO-d6) δ 12.82 (s, 1H), 8.96 (d, J=1.8, 1H), 8.78 (d, J=2.4, 1H), 8.50 (t, J=2.1, 1H), 7.82 (s, 1H), 4.39-4.34 (m, 1H), 3.98 (s, 1H), 3.85-3.81 (m, 1H), 3.77 (s, 2H), 3.53 (dd, J=5.9, 15.1, 1H), 3.20 (s, 3H), 2.31-2.27 (m, 1H), 2.09-2.00 (m, 1H), 1.80-1.72 (m, 1H), 1.37 (d, J=10.5, 2H), 1.12-1.05 (m, 1H), 1.05-0.96 (m, 1H), 0.89 (d, J=7.0, 3H), 0.87 (s, 1H), 0.76 (d, J=6.8, 3H), 0.6 (d, J=6.5, 3H), 0.61-0.55 (m, 1H), 0.54-0.48 (m, 1H), 0.48-0.44 (m, 1H), 0.40-0.34 (m, 2H).
