918511-92-9

1692-25-7

183208-35-7

918511-92-9

Step 1 - Preparation of 5-(pyridin-3-yl)-1H-pyrrolo[2,3-b]pyridine (22): to a mixed solution of 5-bromo-7-azaindole (1, 1.00 g, 5.08 mmol) in water (13.0 mL) and acetonitrile (36 mL) was added sequentially pyridine-3-boronic acid (21, 1.0 g, 8.1 mmol), potassium carbonate (1.79 g, 0.0130 mol), potassium carbonate (1.79 g, 0.0130 mol) and tetrakis(triphenylphosphine)palladium(0) (50.0 mg, 0.043 mmol). The reaction mixture was heated to 170 °C and stirred overnight under nitrogen protection. After completion of the reaction, the mixture was poured into water and extracted with ethyl acetate. The organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using a hexane solution of 25% ethyl acetate as eluent to give a pale yellow solid product 22 (820 mg, 82%).MS (ESI) [M + H]+ = 196.1.