Hydrochloric Acid → 5,6-Dimethyl-2-pyridone

Participants

Reaction Conditions

Reaction Steps

To a suspension of 3-cyano-5,6-dimethyl-2-pyridone (1-013-02) (12.0 g) in water (293 mL) was added conc. hydrochloric acid (293 mL), and the reaction mixture was reflux with stirring in oil-bath at 135° C. After 3 days, the reaction mixture was cooled, and evaporated under reduced pressure. To the residue (24.75 g) were added chloroform (300 mL) and methanol (15 mL), and the reaction mixture was heated in a water bath at 65° C., and the dissolble material was filtered off. Furthermore, the dissolble material was treated by chloroform (200 mL) and methanol (10 mL) in a similar manner to described above. The combined filtrates were evaporated under reduced pressure. To the obtained residue (13.26 g) were added methanol (150 mL) and potassium carbonate (10 g). After stirred at room temperature for 30 min, the dissolble material was filtered off. The filtrate was evaporated under reduced pressure. To the obtained residue (14.7 g) was added chloroform (200 mL), and the dissolble material was filtered off again. The filtrate was evaporated under reduced pressure to give 5,6-dimethyl-2-pyridone (1-013-03) (9.41 g, 94.3%, m.p.: 202-207° C.)

Provenance & Evidence