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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence