The invention discloses a method for preparing
sitafloxacin. The method comprises the following steps: (1) dissolving a compound II and a compound III in
acetonitrile, adding
triethylamine, heating to
reflux, slowly cooling to the temperature of 0 DEG C after reaction is completed, filtering,
drying, thereby obtaining a light yellow compound IV; (2) dissolving a compound IV in a non-protonic
solvent, slowly adding the compound into the pre-cooled
hydrochloric acid, standing and layering the reaction solution after reaction is completed, regulating the pH value of an aqueous phase by using a strong alkaline solution, regulating the pH value by using
ammonium hydroxide, performing vacuum concentration on the
system at
room temperature so as to remove
ammonia gas, separating out lots of white solids, filtering and
drying, thereby obtaining
sitafloxacin. According to the method for preparing
sitafloxacin, disclosed by the invention, impurities produced in the reaction process can be effectively reduced, and the method is simple and convenient in after-treatment, good in refining effect, high in yield and suitable for industrial production.