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

Abstract

In the title compound, C17H12F3NO4S, 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 Ca—H⋯F (a = aromatic) hydrogen bond from an adjacent mol­ecule, resulting in (001) sheets.

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

“…(C27-C32) in B] are 37.42 (8) and 24.84 (7)°, respectively. These values compare with 43.28 (9)° in the Z isomer (Parveen et al, 2014a). The heterocyclic thiazine ring adopts a half-chair conformation.…”

“…More recently, its derivatives were reported as aldose reductase inhibitors (Parveen et al, 2014b). Herein, we report the structure of the title derivative, C 17 H 12 F 3 NO 4 S, which is the E isomer of the previously published isomer 2-[(Z)-1,1-dioxo-2-(2,4,5-trifluorobenzyl)-3,4-dihydro-2H-1,2-benzothiazin-4-ylidene]acetic acid (Parveen et al, 2014a).…”

“…For pharmaceutical and biological properties of 1,2-benzothiazines, see: Zia-ur-Rehman et al (2005); Lombardino et al (1971); Bihovsky et al (2004); For synthetic details of the title compound, see: Parveen et al (2014b). For related structures, see: Yang et al (2012); Parveen et al (2014a). For graph-set analysis, see: Etter et al 1990).…”