反应详情

A mixture of 20 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid, 28.5 g of N-methylpiperazine and 120 ml of anhydrous dimethylsulphoxide is heated at 135°-140° C. for 2.5 hours. The solvent is distilled off under a fine vacuum and the residue is suspended in about 50 ml of water. The solid is filtered off with suction, rinsed with water, dried over calcium chloride in a vacuum drying cabinet at 80° C. and recrystallized from glycol monomethyl ether. 14.5 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinolinecarboxylic acid of decomposition point 248°-250° C. are obtained.

1. temperatureis heated at 135°-140° C. for 2.5 hours
2. distillationThe solvent is distilled off under a fine vacuum
3. filtrationThe solid is filtered off with suction
4. washrinsed with water
5. dry with materialdried over calcium chloride in a vacuum
6. customdrying cabinet at 80° C.
7. customrecrystallized from glycol monomethyl ether