Phosphorus oxychloride → Ethyl 4-chloro-6-methyl-2-oxo-1,2-dihydropyridine-3-carboxylate

Temperature

40 °C

A mixture of ethyl 4-hydroxy-6-methyl-2-oxo-1,2-dihydropyridine-3-carboxylate (3.00 g, 15.2 mmol), phosphorus oxychloride (7.75 mL), n-butyltriethylammonium chloride (13.8 g, 60.8 mmol) and acetonitrile (60 mL) was stirred at 40° C. for 30 min, and then for 30 min under refluxing conditions. After cooling, the reaction mixture was concentrated under reduced pressure, and water was added to the residue. The mixture was extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was washed with a mixed solvent of ethyl acetate-hexane, and dried under reduced pressure to give the title compound (1.45 g, 44%) as a white powder.

1. waitfor 30 min under refluxing conditions
2. temperatureAfter cooling
3. concentrationthe reaction mixture was concentrated under reduced pressure, and water
4. additionwas added to the residue
5. extractionThe mixture was extracted with ethyl acetate
6. washThe extract was washed with brine
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. washThe residue was washed with a mixed solvent of ethyl acetate-hexane
10. customdried under reduced pressure

ORD record

ord-f9fa9514056045e989b58d90f8db6b1d

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486965B2