Dimethylformamide → 2-Chloro-5-fluoro-3-nitropyridine

Temperature

110 °C

5-fluoro-2-hydroxy-3-nitropyridine (11.0 g, 69.4 mmol) prepared in Step 3 was added to a mixed solution of phosphorus oxychloride (38.8 ml, 416 mmol) and N,N-dimethylformamide (537 μl, 6.94 mmol). The reaction mixture was stirred for 5 hours at 110° C. Water (250 ml) was added to the reaction mixture, which was then extracted with ethyl acetate. The organic layer washed with a sodium chloride solution (250 ml) three times, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure. The resulting residue was purified with silica gel column chromatography (ethyl acetate) to give 9.02 g of the titled compound as yellow solid. (Yield: 74%).

1. extractionwas then extracted with ethyl acetate
2. washThe organic layer washed with a sodium chloride solution (250 ml) three times
3. dry with materialdried on anhydrous magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. customThe resulting residue was purified with silica gel column chromatography (ethyl acetate)

ORD record

ord-ceb63d78acf54ce8a2c15c8ecccd4852

Source dataset

uspto-grants-2010_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07662832B2