7-(4-Benzyl-3-methyl-1-piperazinyl)-1-cyclopropyl-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid → 1-Cyclopropyl-7-(3-methyl-1-piperazinyl)-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Steps

To 7-(4-benzyl-3-methyl-1-piperazinyl)-1-cyclopropyl-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (0.30 g) are added acetic acid (10 ml) and 10% Pd-C (50 mg), and the mixture is subjected to catalytic reduction at 70° C. under atmospheric pressure for one hour. After the catalytic reduction, the reaction mixture is cooled and the catalyst is removed by filtration. The filtrate is concentrated, and to the residue is added water, and the mixture is adjusted to about pH 7.5 with sodium hydrogen carbonate, and then is extracted with dichloromethane. The dichloromethane is distilled off, and to the residue is added diethyl ether, and the resulting precipitates are separated by filtration and recrystallized from ethanol to give 7-(3-methyl-1-piperazinyl)-1-cyclopropyl-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (0.16 g), as pale yellow powder, m.p. 206°-208° C.

Provenance & Evidence