反应详情

A solution of 523 g. of 3-phenoxypyridine in 750 ml. of 2-propanol is treated slowly with stirring with 303 g. of 98% sulfuric acid, while maintaining the temperature below 50° C. On cooling to room temperature, the mixture sets up solid. It is heated to 75° C., transferred to an acceptable container and allowed to cool to 50° C. and the crystalline product collected by filtration. The filtrate is allowed to stand at room temperature for 2 hours and the additional crystalline product is collected by filtration. The combined product is dried at reduced pressure to give 3-phenoxypyridine monosulfate, m.p. 103°-107° C. The salt is recrystallized from acetonitrile; after drying at reduced pressure it melts at 107°-109° C.

1. temperatureIt is heated to 75° C.
2. temperatureto cool to 50° C.
3. filtrationthe crystalline product collected by filtration
4. filtrationthe additional crystalline product is collected by filtration
5. customThe combined product is dried at reduced pressure