反应详情

A mixture of 1.95 g of 1-methylamino-6,7,8-trifluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid, 3.05 g of anhydrous piperazine and 20 ml of dry pyridine is refluxed for 6 hours. The solvent is stripped off in vacuo, the residue is taken up in 20 ml of water, the pH is brought to 7-8 with half-concentrated hydrochloric acid, with cooling, and the precipitate is filtered off with suction, washed with ice-water and dried at 100° C. in vacuo. 1.8 g of 1-methylamino-6,8-difluoro-7-(1-piperazinyl)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid of decomposition point 276°-278° C. are obtained.

1. temperatureis refluxed for 6 hours
2. temperaturewith cooling
3. filtrationthe precipitate is filtered off with suction
4. washwashed with ice-water
5. customdried at 100° C. in vacuo