A mixture of 5-bromo-1H-pyrazolo[3,4-b]pyridine (2.00 g, 10.10 mmol), 3-(methoxycarbonyl)phenylboronic acid (2.20 g, 12.12 mmol), sodium bicarbonate (2.2 g, 6.00 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.250 g, 0.202 mmol) in dioxane/water (40 mL/10 mL) was stirred at 110° C. for 15 hours. The mixture was then poured into ice water and extracted with ethyl acetate (3×). The organic layers were combined, dried over sodium sulfate, filtered and concentrated to dryness. Silica gel chromatography of the crude product afforded methyl 3-(1H-pyrazolo[3,4-b]pyridin-5-yl)benzoate (8) (1.65 g, 65% yield) as yellow solids. S: m/z 254.0 (M+H+).
