Diethyl Ether → N-Fluoro-4-methylpyridinium-2-sulfonate

In a reactor, 4-methylpyridine-2-sulfonic acid (3.46 g, 20 mmol) was dissolved in a mixture of acetonitrile (60 ml) and water (6 ml). The reactor was dipped in a cooling bath kept at -20° C., and fluorine gas diluted with nitrogen gas to a concentration of 10% was introduced at a flow rate of 40 ml/min. A total amount of the fluorine gas was 1334 ml (60 mmol). Then, the nitrogen gas alone was introduced at a flow rate of 36 ml/min. for 30 minutes. After the addition of tetrahydrofuran and ethyl ether at -20° C., a crystalline precipitate was recovered by filtration at room temperature. The crystal was washed with ethyl ether and dried under reduced pressure to obtain crystalline N-fluoro-4-methylpyridinium-2-sulfonate (3.04 g, 15.9 mmol). Yield, 80%. A melting point is shown in Table 1. IR and NMR data are as follows:

1. customThe reactor was dipped in a cooling bath
2. customkept at -20° C.
3. additionwas introduced at a flow rate of 40 ml/min
4. additionThen, the nitrogen gas alone was introduced at a flow rate of 36 ml/min. for 30 minutes
5. filtrationa crystalline precipitate was recovered by filtration at room temperature
6. washThe crystal was washed with ethyl ether
7. customdried under reduced pressure

ORD record

ord-bff0a487f3b140bab7d796800392d688

Source dataset

uspto-grants-1994_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05374732