Of Fleroxacin Synthesis Process

We produced fleroxacin by using 6,7,8-trifluoro-1,4-dihydro-4-oxoquino-line-3-ethvlcarbonate as raw material through the following reactions including fluoroethylation,methylpiperazine condensation and hydrolysis. Many factors which effect the reaction,such as reaction temperature, reaction time, ratio of materials and the amounts of solventhave been studied. Results showed that using BrCH₂CH₂F as fluoroethylation reagent wasbetter than using TsOCH₂CH₂F. The optimal reaction conditions of fluoroethylation arethat reaction temperature is about 100℃, the reaction time is 10h, the mol ratio ofmaterials is 1:2.5, the amounts of KI is 4.1g and the amounts of DMF is 40mL.Theoptimal reaction conditions of methylpiperazine condensation are that reactiontemperature is about 75℃and the reaction time is 5h; the amounts of DMSO is 30mLand the amounts of methylpiperazine is 4mL. Fleroxacin is received in acid hydrolysis.At last, the compounds were determined with Melting point, IR, ¹H-NMR and MS.