反应详情

To 25 ml of conc. sulfuric acid was added 6.0 grams of 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid. With ice cooling and stirring, to the solution was added 5.0 g of potassium nitrate in portions. The temperature was slowly elevated to 80° C. at which stirring was continued for 2 hours. The reaction solution was allowed to cool, poured into 200 g of ice water, and allowed to stand overnight. The precipitate was collected by filtration, washed with distilled water, ethanol and diisopropyl ether, and air dried, to give 6.4 g of the title compound.

1. customwas slowly elevated to 80° C. at which
2. stirringstirring
3. temperatureto cool
4. waitto stand overnight
5. filtrationThe precipitate was collected by filtration
6. washwashed with distilled water, ethanol and diisopropyl ether, and air
7. customdried