反应详情

3.44 g of 80% sodium hydride are added in portions, with cooling in ice and stirring, to a solution of 31.9 g of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-cyclopropylaminoacrylate (6) in 100 ml of anhydrous dioxane. The mixture is then stirred at room temperature for 30 minutes and under reflux for 2 hours and the dioxane is removed 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 h. The warm solution is filtered and washed with H2O. The solution is then acidified to pH 1 to 2 with half-concentrated hydrochloric acid, cooling in ice, the precipitate is filtered off with suction, washed with water and dried in vacuo at 100° C. In this manner, 27.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid VII, of melting point 234°-237° C., are obtained.

1. temperaturewith cooling in ice
2. temperatureunder reflux for 2 hours
3. customthe dioxane is removed in vacuo
4. addition6.65 g of potassium hydroxide are added
5. temperaturethe mixture is refluxed for 1.5 h
6. filtrationThe warm solution is filtered
7. washwashed with H2O
8. temperaturecooling in ice
9. filtrationthe precipitate is filtered off with suction
10. washwashed with water
11. customdried in vacuo at 100° C