反应详情

To a solution of 2.85 g. of 4-ethoxypyrazolo[1,5-a]quinoxaline-3-carboxylic acid, ethyl ester in 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 4-ethoxypyrazolo[1,5-a]quinoxaline-3-carboxylic acid is filtered and washed with a small amount of cold water. The product is crystallized from ethanol.

1. concentrationThe mixture is concentrated under reduced pressure
2. dissolutionthe residue dissolved in water
3. filtrationThe solution is filtered
4. filtrationThe precipitated 4-ethoxypyrazolo[1,5-a]quinoxaline-3-carboxylic acid is filtered
5. washwashed with a small amount of cold water
6. customThe product is crystallized from ethanol