title: 2-[(E)-1,1-Dioxo-2-(2,4,5-tri-fluoro-benz-yl)-3,4-di-hydro-2H-1,2-benzo-thia-zin-4-yl-idene]acetic acid.
abstract: In the asymmetric unit of the title compound, C17H12F3NO4S, there are two conformationally similar mol-ecules in which the heterocyclic thia-zine ring adopts a half-chair conformation, with the dihedral angle between the two benzene rings being 24.84 (8) and 37.42 (8)°. In the crystal, the mol-ecules form dimers through cyclic carb-oxy-lic acid O-H⋯O hydrogen-bonding associations [graph set R (2) 2(8)] and are extended into chains along [101] through weak C-H⋯Osulfin-yl hydrogen bonds [graph set R (2) 2(14)]..
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
authors.forename: Shaojuan
authors.initials: S
authors.lastname: Zhu
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
authors.forename: Shagufta
authors.initials: S
authors.lastname: Parveen
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
authors.forename: Changjin
authors.initials: C
authors.lastname: Zhu