Nitric Acid → 5,6-Dimethyl-3-nitro-1,2-dihydropyridin-2-one

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Reaction Steps

5,6-Dimethyl-2-pyridone (1-013-03) (3.695 g) was dissolved in conc. sulfuric acid (38 mL) under ice-cooling, and the reaction mixture was stirred under ice-cooling, and then to the reaction mixture was added dropwise 70% nitric acid (3.53 mL) at 3 to 5° C. as internal temperature for 50 min, and then the reaction mixture was stirred. After 2 h, the reaction mixture was poured gradually into ice and the resulting crystal was filtered. The crystal was washed with water to give 5,6-dimethyl-3-nitro-2-pyridone (1-013-04) (3.102 g, 61.5%, m.p.:251-257 (dec)). Furthermore the aqueous layer was extracted five times with chloroform, the organic layer was dried over magnesium sulfate, and evaporated under reduced pressure. The resulting crystal was filtered to give an additional 5,6-dimethyl-3-nitro-2-pyridone (1-013-04) (271 mg, 5.4%).

Provenance & Evidence