反应详情

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

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