Cao, Ling-feng; Zhang, Yong-tang; Zhang, Jing-zheng published an article in 2011, the title of the article was Improved process of the piperazine condensation for preparation of ciprofloxacin hydrochloride.Reference of 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate And the article contains the following content:
Ciprofloxacin hydrochloride I complying with CP, EP and USP standard was prepared via substitution of cyclopropanecarboxylic acid with anhydrous piperazine. A novel reaction system was developed effectively to reduce the amount of two main byproducts and to increase product yield and quality. Based on the reaction system, other factors were investigated such as the equivalent of piperazine, the reaction temperature and reaction time to determine the optimal parameters of piperazine: the n-pentanol:2-Me pyrrolidone (v:v = 1:1) mixed solvent, 4 mol/L of anhydrous piperazine, 125°C∼130°C and reaction of 8 h, the total yield can reach 81.9%. The experimental process involved the reaction of 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate(cas: 86393-32-0).Reference of 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate
The Article related to ciprofloxacin hydrochloride preparation cyclopropanecarboxylic acid piperazine, Heterocyclic Compounds (More Than One Hetero Atom): Pyrazines and Quinoxalines (Including Piperazines) and other aspects.Reference of 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate
Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics