141-30-0

87199-17-5

914349-19-2

The general procedure for the synthesis of 4-(6-chloro-3-pyridazine)benzaldehyde from 3,6-dichloropyridazine and 4-formylphenylboronic acid was as follows: 3,6-dichloropyridazine (400 mg, 2.69 mmol) was dissolved in dioxane (6 mL) and distilled water (2 mL), and 4-formylphenylboronic acid (321 mg, 2.15 mmol) was added sequentially after complete dissolution, potassium carbonate (920 mg, 6.71 mmol) and PdCl2(dppf)2 (110 mg, 0.13 mmol). The reaction mixture was stirred at 90 °C for the reaction. After completion of the reaction, the reaction mixture was diluted with dichloromethane, washed sequentially with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (eluent: 40% ethyl acetate/hexane) to afford 4-(6-chloropyridazin-3-yl)benzaldehyde (148 mg, 25% yield) as a white solid.