反应详情

6-(2-Chloropyridin-3-yl)-1-methyl-1H-benzimidazole was synthesized in the similar manner to the preparation of 5-(2-chloropyridin-3-yl)-1H-indazole by heating the mixture of 6-bromo-1-methyl-1H-benzimidazole (1.0 g, 4.7 mmole), 2-chloro-3-pyridine boronic acid pinacol ester (1.4 g, 5.8 mmol), Pd(PPh3)4 (330 mg, 0.28 mmol) and 2M aq.Na2CO3 (7 mL, 14 mmol) in 1,4-dioxane (60 mL). Upon extractive work-up with CH2Cl2 and purification (Combiflash® companion System® with RediSep® silica gel column 24 g, 3% MeOH/EtOAc as a eluting solvent) provided off-white solid of 6-(2-chloropyridin-3-yl)-1H-benzimidazole (430 mg, 36%). 1H NMR (DMSO-d6): δ 8.42 (dd, 1H, J=1.7 and 4.7 Hz), 8.24 (s, 1H), 7.91 (dd, 1H, J=1.7 and 7.6 Hz), 7.60 (d, 1H, J=8.8 Hz), 7.67 (app d, 1H, J=0.7 Hz), 7.53 (dd, 1H, J=J=4.7 and 7.6 Hz), 7.29 (dd, 1H, J=1.7 and 8.8 Hz), 3.86 (s, 3H LCMS: rt 3.85 min (A), purity 94%, MS (m/e) 244 (MH+)

1. temperatureby heating
2. customUpon extractive work-up with CH2Cl2 and purification (Combiflash® companion System® with RediSep® silica gel column 24 g, 3% MeOH/EtOAc as a eluting solvent)