1-环丙基-7-氯-6-(1-哌嗪基)-4-氧-1,4-二氢-3-喹啉羧酸盐酸盐的熔化与离解性质研究

1－环丙基－7－氯－6－（1－哌嗪基）－4－氧－1，4－二氢－3－喹啉羧酸盐酸盐为环丙沙星合成中主要的杂质之一，研究其物化性质对于改善环丙沙星的结晶分离提纯具有重要意义。本文研究了1－环丙基－7－氯－6－（1－哌嗪基）－4－氧－1，4－二氢－3－喹啉羧酸盐酸盐的熔化，分解特性，溶解度与离子强度，温度和pH值的关系，并测定了该物质的离解常数，估算了该物质在水溶液中的活度积。

Study on the Melting and Dissociation Properties of 1-Cyclopropyl-7-Chloro-6-(1-Piperazinyl)-4-Oxo-1,4-Dihydroquinoline-3-Carboxylic Acid Hydrochloride

cyclopropyl-7-chloro-6-(1-piperazinyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid is the main impurity in the industrial manufacture of ciprofloxacin. The investigation of its physicochemical properties has important significance in the improvement of the crystallization and purification process of ciprofloxacin. The melting andde composition properties of 1-cyclopropy l-7-chloro-6- (1-piperazinyl)-4- oxo-1,4- dihydroquinoline -3-carboxylic acid hydrochloride and the relationships between the solubility and the ion strength, temperature and pH was studied systematically in this paper. The micro- and macro-dissolution constants and the solubility product have been estimated using the experimental solubility data by the proton equilibrium theory.