反应详情

3.44 g of 80% pure sodium hydride are added in portions to a solution of 31.9 g of ethyl 2-(2,4-dichloro-5-fluoro-benzoyl)-3-cyclopropylamino-acrylate (6) in 100 ml of anhydrous dioxane, while cooling with ice and stirring. The mixture is then stirred at room temperature for 30 minutes and under reflux for 2 hours and the dioxane is stripped off in vacuo. The residue (40.3 g) is suspended in 150 ml of water, 6.65 g of potassium hydroxide are added and the mixture is refluxed for 1.5 hours. The warm solution is filtered and the residue is rinsed with H2O. The filtrate is then acidified to pH 1-2 with half-concentrated hydrochloric acid, while cooling with ice, and the precipitate is filtered off with suction, washed with water and dried at 100° C. in vacuo. 27.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid VIa of melting point 234° to 237° C. are obtained in this manner.

1. temperaturewhile cooling with ice
2. stirringThe mixture is then stirred at room temperature for 30 minutes
3. temperatureunder reflux for 2 hours
4. temperaturethe mixture is refluxed for 1.5 hours
5. filtrationThe warm solution is filtered
6. washthe residue is rinsed with H2O
7. temperaturewhile cooling with ice
8. filtrationthe precipitate is filtered off with suction
9. washwashed with water
10. customdried at 100° C. in vacuo