A mixture of 1-(4-methoxybenzyl)-4-(5-chloro-2-fluoro-4-nitrophenoxy)-3-iodo-1H-pyrazolo[3,4-b]pyridine (2.85 g, 5.14 mmol), SnCl2 dihydrate (4.64 g, 20.6 mmol) and EtOH (70 mL) was heated to 70° C. for 8 hours. The reaction mixture was cooled to room temperature, diluted with EtOAc, washed with saturated aqueous Na2CO3, dried over sodium sulfate and concentrated. The residue was purified by flash column chromatography (5% MeOH in CH2Cl2) to afford the product (2.02 g, 64% yield) as a light yellow solid. LRMS (APCI pos) m/e 524.9 (M+H).
