反应详情

A mixture of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methyl-4-oxo-3-quinolinecarboxylic acid (200 mg), piperazine (250 mg) in anhydrous DMSO (2 ml) was stirred at 70° to 80° C. for 4 hours. After the reacting mixture was concentrated under reduced pressure, to the resulting residue was added methanol and the resulting precipitate was filtered off. After the filtrate was concentrated under reduced pressure, the resulting residue was purified by silica gel column chromatography eluting chloroform-methanol (20:1) chloroform-methanol-concentrated aqueous ammonia (10:10:1) and further purified by preparative thin layer chromatography eluting chloroform-methanol (20:1)→chloroform methanol-concentrated aqueous ammonia (10:10:1→10:10:3) to give the title compound (46 mg) as redish powder, mp 300° C.

1. concentrationAfter the reacting mixture was concentrated under reduced pressure, to the resulting residue
2. additionwas added methanol
3. filtrationthe resulting precipitate was filtered off
4. concentrationAfter the filtrate was concentrated under reduced pressure
5. customthe resulting residue was purified by silica gel column chromatography
6. washeluting chloroform-methanol (20:1) chloroform-methanol-concentrated aqueous ammonia (10:10:1)
7. customfurther purified by preparative thin layer chromatography
8. washeluting chloroform-methanol (20:1)