rel-(2R,6S)-2,6-dimethylpiperazine → 3-Quinolinecarboxylic acid, 1,4-dihydro-5-amino-1-cyclopropyl-7-(3,5-dimethyl-1-piperazinyl)-6-fluoro-4-oxo-, cis-

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Reaction Steps

A mixture of 280 mg of 5-amino-1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, 542 mg of cis-2,6-dimethylpiperazine and 10 ml of pyridine was heated under reflux for 2.5 hours. The solvent was evaporated under reduced pressure. To the residue was added a 1N aqueous solution of sodium hydroxide, and the insoluble matter was removed by filtration. A 10% aqueous solution of acetic acid was added to the filtrate to adjust its pH to 8. The solution was then extracted with chloroform. The chloroform layer was dried with sodium sulfate, and concentrated under reduced pressure. Acetonitrile was added to the residue, and the mixture was cooled with ice. The crystals were collected by filtration, and recrystallized from aqueous ammonia to give 250 mg of 5-amino-1-cyclopropyl-6-fluoro-7-(cis-3,5-dimethyl-1-piperazinyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid. m.p. 253°-254° C.

Provenance & Evidence