Reaction #65759

Reaction equation

sodium nitrite

2-amino-3,4-diethoxycarbonyl-6-(4-methoxyphenyl)pyridine

hydrochloric acid

dioxane

→

3,4-Diethoxycarbonyl-6-(4-methoxyphenyl)-2-pyridone

Solvents

water

Conditions

Workup

1. 1
   Temperaturecooling
2. 2
   workup.DISTILLATIONThe solvent was distilled off
3. 3
   Extractionfollowed by extraction with ethyl acetate
4. 4
   WashThe organic layer was washed with a saturated aqueous solution of sodium chloride
5. 5
   Otherdried
6. 6
   workup.DISTILLATIONThe solvent was distilled off
7. 7
   OtherThe resulting crude crystals were recrystallized from ethanol

Procedure

To 100 mg of 2-amino-3,4-diethoxycarbonyl-6-(4-methoxyphenyl)pyridine were added 2 ml of 1N hydrochloric acid and 5 ml of dioxane, and thereto was added dropwise a solution of 26 mg (1.3 eq.) of sodium nitrite dissolved in 0.5 ml of water under ice-cooling. The mixture was stirred at room temperature overnight. The solvent was distilled off. The residue was neutralized with sodium hydrogencarbonate, followed by extraction with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium chloride and dried. The solvent was distilled off. The resulting crude crystals were recrystallized from ethanol.

Source