反应详情

12 g (40 mmol) of the product from Example A in 100 ml of pyridine are heated with 17.2 g (0.2 mole) of piperazine under reflux for 5 hours. The mixture is concentrated in vacuo, the residue is stirred with 120 ml of water and the pH is adjusted to 5 with 2N hydrochloric acid. The precipitate is filtered off with suction, washed with water and methanol, boiled in 80 ml of methanol and dried. 12.3 g (84% of theory) 6-chloro-1-cyclopropyl-8-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid of melting point 295°-298° (with decomposition) are obtained.

1. temperatureunder reflux for 5 hours
2. concentrationThe mixture is concentrated in vacuo
3. filtrationThe precipitate is filtered off with suction
4. washwashed with water and methanol
5. customdried