In a 25-mL round-bottomed two-necked flask, 4 mL of methanol was added, followed by 4-methoxypyridine (0.5 mmol, 54.6 mg), 30% H2O2 (6.0 eq., 0.3 mL), potassium carbonate (4.0 eq., 276.4 mg), and SO2F2 gas was introduced into the gas stream by using two straight pistons with straight bends and a hose to connect a balloon on one side. The reaction was carried out under sealed conditions with stirring for 20-40 min at room temperature of 23-32 C. After the reaction, the potassium carbonate solid was removed by filtration, dried with anhydrous sodium sulfate to remove water and filtered again, and the solvent was concentrated to obtain the crude product, which was finally isolated and purified by column chromatography to give 40.3 mg of 4-methoxypyridinium nitride in a yield of 65.4%.
