title: Marbofloxacin.
abstract: IN THE TITLE COMPOUND, [SYSTEMATIC NAME: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb-oxy-lic acid], C(17)H(19)FN(4)O(4), the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39 (2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH(2) group at the flap displaced by 0.650 (2) Å from the plane through the other five atoms. The mol-ecular structure exhibits an S(6) ring motif, owing to an intra-molecular O-H⋯O hydrogen bond. In the crystal, weak C-H⋯F hydrogen bonds link mol-ecules into layers parallel to the ab plane.
authors.forename: Jin
authors.initials: J
authors.lastname: Shen
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Qian
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Gu
authors.forename: Xiu-Rong
authors.initials: XR
authors.lastname: Hu