The invention relates to a preparation process of lavo-
ofloxacin and
ofloxacin which are anti-infectious medicaments, belonging to the synthetic process with tetrafluorobenzoic aid as
raw material. The preparation method is characterized in that (2, 3, 4, 5-phenyl
tetrafluoride formyl)
ethyl acetate and DMFA react for 1.0-1.5h in
toluene at 50-55 DEG C with the existence of acylating catalyst; the
reaction product is washed by water, and an aqueous layer is separated; at 30-35 DEG C, L-amino
propanol is dripped in an oil layer to carry out replacement reaction for 1.5-2.0h;
toluene is decompressed, recovered and dried proper quantity of DMF is added to the oil layer for diluting; the diluted oil layer is dripped into back-flow DMF with the existence of
anhydrous potassium fluoride to carry out back-flow reaction for 6h; DMF is recovered, water is added for
centrifugation, acid is added to the obtained
solid to be hydrolyzed to prepare lavo-perfluorocarboxylic acid, the lavo-perfluorocarboxylic acid reacts with N-methyl
piperazine in DMSO at 90-110 DEG C by taking
triethylamine as an acid-binding agent, and the lavo-
ofloxacin is obtained after the fine purification of the product of reaction. The process improves the reaction condition of (2, 3, 4, 5-phenyl
tetrafluoride formyl)
ethyl acetate and DMFA, lowers the
reaction temperature, shortens the reaction time and improves the reaction yield of lavo-fluoro ester serving as a
reaction intermediate by 20 percent.