Reaction Steps
2-[4-(4-Methyl-[1,4]diazepan-1-yl)-butoxy]-isonicotinonitrile. To a solution of 1-methyl-[1,4]diazepane (21.3 g, 185 mmol, 2.0 equiv) and 4-chloro-butan-1-ol (10.0 g, 92.6 mmol, 1.0 equiv) in 1-butanol (200 mL) were added K2CO3 (38.0 g, 278 mmol, 3.0 equiv) and NaI (13.9 g, 92.6 mmol, 1.0 equiv). The mixture was warmed to 95° C. and stirred for 36 h. The mixture was then cooled to rt, diluted with water, and extracted with chloroform (3×100 mL). The combined extracts were washed with brine, dried (MgSO4), filtered, and concentrated. Purification by Method 2 afforded 9.3 g of 4-(4-methyl-[1,4]diazepan-1-yl)-butan-1-ol with a small unidentified impurity. A portion of the impure alcohol (5.0 g) was dissolved in DMF (50 mL) and cooled to 0° C. Sodium hydride (60% dispersion in oil, 1.29 g, 32.2 mmol, 1.2 equiv) was added. The mixture was warmed to rt, stirred for 1 h, and then re-cooled to 0° C. A solution of 2-chloro-isonicotinonitrile (3.72 g, 26.8 mmol, 1.0 equiv) in DMF (25 mL) was added dropwise. The mixture was stirred at rt for 18 h, then was diluted with water (25 mL) and satd. aq. NaHCO3 (100 mL), and was extracted with chloroform (3×100 mL). The combined extracts were washed with brine, dried (Na2SO4), filtered and concentrated. Purification by Method 2 afforded the title compound (1.0 g). MS (electrospray): mass calculated for C16H24N4O, 288.20; m/z found, 289.4 [M+H]+. 1H NMR (400 MHz, CDCl3): 8.28 (dd, J=4.4 Hz, 0.8 Hz, 1H), 7.05 (dd, J=3.9, 1.1 Hz, 1H) 6.96 (s, 1H), 4.33 (t, J=6.6 Hz, 2H), 2.75-2.68 (m, 4H), 2.65-2.57 (m, 4H), 2.56-2.49 (m, 2H), 2.35 (s, 3H), 1.84-1.74 (m, 4H), 1.66-1.55 (m, 2H). B. 5-Fluoro-4-methyl-2-{2-[4-(4-methyl-[1,4]diazepan-1-yl)-butoxy]-pyridin-4-yl}-1H-benzoimidazole. To a stirred solution of 2-[4-(4-methyl-[1,4]diazepan-1-yl)-butoxy]-isonicotinonitrile (1.0 g, 3.47 mmol, 1.0 equiv) in toluene (5.0 mL) at 0° C. was added 1.0 M diisobutylaluminum hydride in toluene (5.2 mL, 5.2 mmol, 1.5 equiv). After 3 h, methanol (9 mL) and 1.0 M H2SO4 (10 mL) were added. The mixture was stirred for 30 min, and then 1.0 M NaOH (10 mL) was added, followed by satd. aq. sodium potassium tartrate (40 mL) and dichloromethane (100 mL). After stirring for 30 min, the mixture was extracted with chloroform (3×50 mL) and the combined extracts were washed with brine, dried (Na2SO4), filtered, and concentrated. The residue was partially purified by Method 2 to afford 268 mg of a mixture of 2-[4-(4-methyl-[1,4]diazepan-1-yl)-butoxy]-pyridine-4-carbaldehyde and several other unidentified products. A portion of the impure 2-[4-(4-methyl-[1,4]diazepan-1-yl)-butoxy]-pyridine-4-carbaldehyde (63 mg), 4-fluoro-3-methyl-benzene-1,2-diamine (30.3 mg), and Na2S2O5 (53.4 mg) were stirred in DMF (3 mL) at 90° C. for 18 h. The reaction mixture was loaded directly on silica gel and purified by Method 2, which afforded 5.0 mg of the title compound. MS (electrospray): mass calculated for C23H30FN5O, 411.24; m/z found, 412.5 [M+H]+. 1H NMR (400 MHz, CD3OD): 8.27 (dd, J=4.8, 0.5 Hz, 1H), 7.63 (dd, J=4.0, 1.4 Hz, 1H), 7.52-7.40 (m, 2H), 7.10-7.01 (m, 1H), 4.27 (t, J=6.3 Hz, 2H), 2.86-2.77 (m, 4H), 2.77-2.68 (m, 4H), 2.65-2.57 (m, 2H), 2.53 (s, 3H), 2.37 (s, 3H), 1.90-1.66 (m, 6H).
