反应详情

A mixture of 1-propyl-6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 0.95 g (3.3 millimole) and piperazine hexahydrate 10 g (50 millimole) was heated in a sealed tube at 125°-135° C. (inner temperature) for 22 hours. After cooling, the reaction mixture was evaporated under vacuum, and the residue was acidified with acetic acid and the insoluble matters were removed by filtration. The filtrate was neutralized with an aqueous solution of caustic soda, extracted with the use of CHCl3, washed with water, dried over anhydrous Na2SO4, and the solvent was evaporated off. The residue was dissolved in dilute hydrochloric acid, reprecipitated with the addition of ethanol. The precipitated crystals were collected by filtration, washed with ethanol and dried to obtain 0.2 g (16%) of 1-propyl-6-fluoro-7-(1-piperazinyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride. Colorless powders.

1. temperaturewas heated in a sealed tube at 125°-135° C. (inner temperature) for 22 hours
2. temperatureAfter cooling
3. customthe reaction mixture was evaporated under vacuum
4. customthe insoluble matters were removed by filtration
5. extractionextracted with the use of CHCl3
6. washwashed with water
7. dry with materialdried over anhydrous Na2SO4
8. customthe solvent was evaporated off
9. dissolutionThe residue was dissolved in dilute hydrochloric acid
10. customreprecipitated with the addition of ethanol
11. filtrationThe precipitated crystals were collected by filtration
12. washwashed with ethanol
13. customdried