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 under refluxing conditions for 30 min. After cooling, the reaction mixture was concentrated under reduced pressure, water was added to the residue and 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 ethyl acetate-hexane mixed solution, and dried under reduced pressure to give the title compound (1.45 g, 44%) as a white powder.

1. temperatureAfter cooling
2. concentrationthe reaction mixture was concentrated under reduced pressure, water
3. additionwas added to the residue
4. extractionthe mixture was extracted with ethyl acetate
5. washThe extract was washed with brine
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. washThe residue was washed with ethyl acetate-hexane mixed solution
9. customdried under reduced pressure

ORD record

ord-68ae94e440ca4b78a11f49d01d72fc47

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08399449B2