反应详情

To 40 ml of conc. sulfuric acid was added 4 g of 1-(2,4-difluorophenyl)-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid. Potassium nitrate (3.6 mg) was added in portions to the solution, which was stirred for 1 hour at room temperature. The reaction solution was poured into ice water and stirred overnight. The precipitated solid was collected by filtration and washed with water, ethanol and diethyl ether to give 4.2 g of the title compound.

1. stirringstirred overnight
2. filtrationThe precipitated solid was collected by filtration
3. washwashed with water, ethanol and diethyl ether