The invention discloses a preparation method of
ciprofloxacin hydrochloride. The existing synthesis method generally uses
isoamyl alcohol and the like as
solvent, thus having the problems of strong smell, difficult
biodegradation and higher environmental
pollution. If the
solvent such as the
isoamyl alcohol and the like is used, more alkali insoluble substances and acidic insoluble substances are generated in
recovery after the reaction, so that the insoluble substances are needed to be treated by purification through the steps such as alkali-dissolving heat-filtering call-back throw filter, acidic-dissolving heat-filtering call-back throw filter, salifying decoloration heat-filtering and the like, the process
route is longer, and the product yield is lower. The preparation method of the
ciprofloxacin hydrochloride selects the proper
solvent as reaction medium, firstly leads
cyclopropane carboxylic acid and
piperazine to have
piperazine reduction reaction and then leads the
reaction product to be salified together with
hydrochloric acid. In the reaction process, less alkali insoluble substances and acidic insoluble substances are generated in the reaction process, and the
ciprofloxacin hydrochloride can be obtained by salifying decoloration heat-filtering, separation by
crystallization, throw filter, rinsing and
drying after being directly cooled and leached, so that the time for occupying equipment and the time of working procedures are shortened, and the production efficiency of a workshop is improved.