The invention provides a synthetic method of
moxifloxacin hydrochloride. The synthetic method comprises the following steps: by taking a primary ring chelate as shown in a formula (I) and (S, S)-2,8-diazabicyclo[4.3.0]
nonane as raw materials and taking
triethylamine as an acid absorber, carrying out
condensation reaction in
acetonitrile sufficiently; and concentrating, treating, then dissolving, carrying out acidolysis and salifying, crystallizing, filtering, washing and
drying to obtain the
moxifloxacin hydrochloride, wherein a weight ratio of the primary ring chelate to
acetonitrile to
triethylamine to (S, S)-2,8-diazabicyclo[4.3.0]
nonane is 1 to (2-10) to (0.08-0.96) to (0.30-0.59). The synthetic method is characterized in that a
condensation reaction temperature is larger than and equal to 30 DEG C and lower than 70 DEG C. The synthetic method has the following technical effects that
nucleophilic substitution reaction is carried out in
acetonitrile at a temperature not lower than 30 DEG C but lower than 70 DEG C, the
reaction conditions are gentle, the production of impurities is greatly reduced and the
energy resources are saved. After acetonitrile is evaporated, the treatment method is simple and rapid, acidification is carried out in
alcohol to obtain
moxifloxacin hydrochloride, and thus, the synthetic method is suitable for industrial production.