Phosphorus oxychloride → 2-Pyridone

Participants

Reaction Conditions

Reaction Steps

3.3 g (10.9 mmol) of 3-(4-chlorophenyl)-2,4-dioxo-1-methyl-6-trifluoromethyl-1,2,3,4-tetrahydropyridine was added to 8.3 g (42.3 mmol) of phosphorus oxychloride and 30 ml of diethylaniline, followed by stirring at from 100 to 120° C. for 4 hours. The reaction solution was distilled off under reduced pressure, and ethyl acetate was added to the obtained residue, followed by washing with water and a saturated sodium hydrogencarbonate aqueous solution. The organic layer was dried over anhydrous magnesium sulfate. The organic layer was distilled off under reduced pressure, and the obtained residue was separated and purified by high performance liquid chromatography to obtain 1.3 g (yield: 37%) of the desired 2-pyridone compound (Compound No. 11-1) and 1.0 g (yield: 29%) of the 4-pyridone compound (Compound No. 13-1), respectively.

Provenance & Evidence