反应详情

To a solution of 3 g of 5,6-dihydro-1,5-dioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid, ethyl ester of hot ethanol, there is added 10 ml of 10% aqueous sodium hydroxide and the mixture refluxed for 2 hours. The mixture is concentrated under reduced pressure and the residue dissolved in water. The solution is filtered and neutralized with dilute hydrochloric acid. The precipitated 5,6-dihydro-1,5-dioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid is filtered and washed with a small amount of cold water. The product is crystallized from ethanol.

1. temperaturethe mixture refluxed for 2 hours
2. concentrationThe mixture is concentrated under reduced pressure
3. dissolutionthe residue dissolved in water
4. filtrationThe solution is filtered
5. filtrationThe precipitated 5,6-dihydro-1,5-dioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid is filtered
6. washwashed with a small amount of cold water
7. customThe product is crystallized from ethanol