Compound (125a) (0.500 g), 2-picoline-borane complex (0.166 g), and dimethylamine (0.216 mL) were dissolved in acetic acid (1.0 mL) and methanol (10 mL), followed by stirring at room temperature for 12 hr. The reaction solution was concentrated, and the residue was purified by basic silica gel column chromatography (hexane/ethyl acetate) to obtain 3-{(dimethylamino)methyl}-4-{4-iodo-3-isopropyl-1H-pyrazolo[3,4-b]pyridin-1-yl}benzonitrile (0.213 g, 40%). This 3-{(dimethylamino)methyl}-4-{4-iodo-3-isopropyl-1H-pyrazolo[3,4-b]pyridin-1-yl}benzonitrile was dissolved in DMSO (1.6 mL), and a hydrogen peroxide solution (30 wt %) (0.060 mL) and a 4 mol % aqueous sodium hydroxide solution (0.132 mL) were added to the resulting solution, followed by stirring at room temperature for 20 min. Water was added to the reaction solution, and the precipitate was collected by filtration and was dried under reduced pressure to obtain 3-{(dimethylamino)methyl}-4-{4-iodo-3-isopropyl-1H-pyrazolo[3,4-b]pyridin-1-yl}benzamide (0.144 g, 65%). According to Example 97(2), compound (126) (64%) was prepared as a white solid using 3-{(dimethylamino)methyl}-4-{4-iodo-3-isopropyl-1H-pyrazolo[3,4-b]pyridin-1-yl}benzamide instead of compound (97a) and using 4-(1-methyl-1H-pyrazol-4-yl)-1H-imidazole hydrochloride instead of 4-phenyl-1H-imidazole.
