Sodium Nitrate → 5-fluoro-2-methoxypyridine

5-amino-2-methoxypyridine (81.5 g, 0.657 mol) was dissolved in a mixture of concentrated hydrochloric acid (120 ml) and water (530 ml). A solution of sodium nitrate (56.5 g, 0.819 mol) in water (100 ml) was added at −5° C. to the solution. The reaction mixture was stirred for 45 minutes at room temperature and sodium nitrate (56.5 g, 0.819 mol) was further added thereto. Hexafluorophosphoric acid (132 ml) was added to the reaction mixture, which was then stirred for 20 minutes at room temperature. The reaction mixture was filtered to obtain a solid, which was washed with water and ethyl ether and then dried under reduced pressure. The resulting compound was heated for 15 minutes at 150° C., dissolved in dichloromethane, and then washed with 3N sodium hydroxide solution. The organic layer was dried on anhydrous magnesium sulfate, concentrated under reduced pressure, and then fractionally distilled to give 22.6 g of the titled compound as colorless oil. (Yield: 27%).

1. stirringwas then stirred for 20 minutes at room temperature
2. filtrationThe reaction mixture was filtered
3. customto obtain a solid, which
4. washwas washed with water and ethyl ether
5. customdried under reduced pressure
6. temperatureThe resulting compound was heated for 15 minutes at 150° C.
7. dissolutiondissolved in dichloromethane
8. washwashed with 3N sodium hydroxide solution
9. dry with materialThe organic layer was dried on anhydrous magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. distillationfractionally distilled

ORD record

ord-b5b7fc632b394349b3241fa75290883d

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08188114B2