Reaction Steps
To a solution of 6-isopropyl-2-(2-thiazol-2-yl-imidazol-1-ylmethyl)-1H-imidazo[4,5-c]pyridine (160 mg, 0.493 mmol) in DMF (1.0 mL) at room temperature under N2 is added Cs2CO3 (168 mg, 0.518 mmol) followed by iodoethane (0.047 mL, 0.592 mmol). The mixture is stirred at room temperature for 1 h and then diluted with water and extracted twice with CH2Cl2. The combined extracts are dried over K2CO3 and concentrated. The residue is purified by preparative TLC, developing with 15:1 CHCl3-MeOH (+0.5% Et3N). The less polar (top) band affords 3-ethyl-6-isopropyl-2-{[2-(1,3-thiazol-2-yl)-1H-imidazol-1-yl]methyl}-3H-imidazo[4,5-c]pyridine. 1H NMR (CDCl3, 300 MHz) δ 8.70 (d, J=1.2 Hz, 1H), 7.83 (d, J=3.0 Hz, 1H), 7.53 (d, J=0.9 Hz, 1H), 7.39 (d, J=3.0 Hz, 1H), 7.18 (d, J=0.9 Hz, 1H), 7.14 (d, J=0.9 Hz, 1H), 6.32 (s, 2H), 4.32 (q, J=7.2 Hz, 2H), 3.18 (sept, J=6.9 Hz, 1H), 1.34 (d, J=6.9 Hz, 6H), 1.17 (t, J=7.2 Hz, 3H) ppm. The more polar (bottom) band affords 74 mg (43%) of 1-ethyl-6-isopropyl-2-{[2-(1,3-thiazol-2-yl)-1H-imidazol-1-yl]methyl}-1H-imidazo[4,5-c]pyridine. 1H NMR (CDCl3, 300 MHz) δ 9.01 (s, 1H), 7.83 (d, J=3.2 Hz, 1H), 7.38 (d, J=3.2 Hz, 1H), 7.15 (8, 1H), 7.12 (s, 1H), 7.09 (s, 1H), 6.32 (s, 2H), 4.21 (q, J=7.2 Hz, 2H), 3.17 (sept, J=6.8 Hz, 1H), 1.34 (d, J=6.8 Hz, 6H), 1.10 (t, J=7.2 Hz, 3H) ppm.
