1214337-05-9

1346555-30-3

1214337-05-9

Step 2: Synthesis of methyl 6-chloro-5-fluoropyridinecarboxylate 5-Fluoro-2-(methoxycarbonyl)pyridine-1-oxide (100 mg, 0.584 mmol) was dissolved in phosphorus trichloride (2 mL) and heated to reflux for 4 h under nitrogen protection. Upon completion of the reaction, the reaction solution was quenched by slow pouring into ice (15 g) and subsequently extracted with dichloromethane (30 mL × 2). The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated. The resulting residue was purified by medium pressure liquid chromatography (MPLC) with 20% ethyl acetate/hexane as eluent to give 88 mg of white solid product in 79% yield.