2-[(Z)-1,1-Dioxo-2-(2,4,5-tri­fluoro­benz­yl)-3,4-di­hydro-2H-1,2-benzo­thia­zin-4-yl­idene]acetic acid

In the title compound, C(17)H(12)F(3)NO(4)S, the heterocyclic thia­zine ring adopts a half-chair conformation and the dihedral angle between the benzene rings is 43.28 (9)°. The α,β-unsaturated C=C group is inclined at an angle of 21.0 (3)° to the benzene ring of the benzo­thia­zine moiety. In the crystal, inversion dimers linked by pairs of carb­oxy­lic acid O—H⋯O hydrogen bonds generate R (2) (2)(8) loops. Each of the F atoms accepts a C(a)—H⋯F (a = aromatic) hydrogen bond from an adjacent mol­ecule, resulting in (001) sheets.