Fleroxacin hydrochloride hydrate

In the structure of the title compound, 4‐[3‐carboxy‐6,8‐di­fluoro‐1‐(2‐fluoro­ethyl)‐1,4‐di­hydro‐4‐oxo‐7‐quinolyl]‐1‐methyl­piperazinium chloride hydrate, C₁₇H₁₉F₃N₃O₃⁺·­Cl^?·­H₂O, the quinoline and its substituents, except for the fluoro­ethyl group, are coplanar, while the piperazinium moiety exists in a chair form. There are π–π‐stacking interactions between the quinoline rings, and intra‐ and intermolecular hydrogen bonds in the crystal.