反应详情

A mixture of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxo-3-quinolinecarboxylic acid (200 mg), anhydrous piperazine (180 mg) and anhydrous dimethyl sulfoxide (DMSO; 3 ml) was stirred for 2.5 hours at 70° to 80° C. on an oil bath. The reacting mixture was concentrated under reduced pressure and cold water was added to the residue. The precipitate was collected by filtration and recrystallized from a mixed solution of dichloromethane-methanol (1:1) to give the title compound (40 mg) as pale yellow prisms, mp 187° C. (decompd.).

1. concentrationThe reacting mixture was concentrated under reduced pressure and cold water
2. additionwas added to the residue
3. filtrationThe precipitate was collected by filtration
4. customrecrystallized from a mixed solution of dichloromethane-methanol (1:1)