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 was 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 was 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-972032d762cf4e38b133ead06e28043f

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08188114B2