To a stirred solution of ethyl 6-bromo-1-isopropyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylate (0.3 g, 0.964 mmol) in acetonitrile (10 mL), K2CO3 (0.26 g, 1.93 mmol) and 1-methylpiperazine (0.289 g, 2.892 mmol) was added. The reaction mixture was refluxed for 3 h. On completion of reaction, acetonitrile was removed under reduced pressure and water was added to it. Extraction was carried out using DCM; the combined organic layers were washed with water, brine and dried over anhydrous Na2SO4. Solvent was removed under reduced pressure to obtain the desired intermediate (0.32 g, 94.9%).
