3-Benzoyl-4-hydr­oxy-2-methyl-2H-1,2-benzothia­zine 1,1-dioxide

Matloob Ahmad; Hamid Latif Siddiqui; Saeed Ahmad; Sana Aslam; Masood Parvez

doi:10.1107/S1600536810011025

. 2010 Mar 27;66(Pt 4):o968. doi: 10.1107/S1600536810011025

3-Benzoyl-4-hydroxy-2-methyl-2H-1,2-benzothiazine 1,1-dioxide

Matloob Ahmad ^a, Hamid Latif Siddiqui ^b,^*, Saeed Ahmad ^c, Sana Aslam ^b, Masood Parvez ^d

PMCID: PMC2983979 PMID: 21580768

Abstract

In the title molecule, C₁₆H₁₃NO₄S, the heterocyclic thiazine ring adopts a half-chair conformation with the S and N atoms displaced by 0.410 (3) and 0.299 (3) Å, respectively, on opposite sides of the mean plane formed by the remaining ring atoms. The crystal structure is stabilized by intermolecular hydrogen bonds of the types O—H⋯O and C—H⋯O; the former result in dimers lying about inversion centers and the latter form chains of molecules running along the c axis. In addition, intramolecular O—H⋯O links are present.

Related literature

For 1,2-benzothiazine derivatives as anti-inflammatory drugs (NSAIDs), see: Lombardino et al. (1971 ▶); Soler (1985 ▶); Carty et al. (1993 ▶); Turck et al. (1995 ▶). For the synthesis of benzothiazine derivatives, see: Siddiqui et al. (2007 ▶); Ahmad, Siddiqui, Zia-ur-Rehman et al. (2010 ▶). For related structures, see: Siddiqui et al. (2008 ▶); Ahmad, Siddiqui, Rizvi et al. (2010 ▶).

Experimental

Crystal data

C₁₆H₁₃NO₄S
M _r = 315.33
Triclinic,
a = 6.8342 (3) Å
b = 9.9085 (3) Å
c = 10.7234 (4) Å
α = 83.257 (2)°
β = 79.481 (2)°
γ = 85.113 (2)°
V = 707.50 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 173 K
0.12 × 0.10 × 0.08 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1997 ▶) T _min = 0.971, T _max = 0.981
7177 measured reflections
4080 independent reflections
3665 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.113
S = 1.09
4080 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶); data reduction: SCALEPACK (Otwinowski & Minor, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011025/jh2140sup1.cif

e-66-0o968-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810011025/jh2140Isup2.hkl

e-66-0o968-Isup2.hkl^{(195.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3O⋯O4	0.84	1.80	2.5365 (15)	146
O3—H3O⋯O1ⁱ	0.84	2.56	3.0108 (15)	115
C3—H3⋯O1ⁱⁱ	0.95	2.50	3.2627 (18)	138

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

HLS is grateful to Institute of Chemistry, University of the Punjab, for financial support.

supplementary crystallographic information

Comment

Oxicam, a class of non steroidal anti-inflammatory drugs (NSAIDs) consists of benzothiazine derivatives which are found to be potent anti-inflammatory and analgesic agents, e.g., piroxicam (Lombardino et al., 1971), droxicam (Soler, 1985), ampiroxicam (Carty et al., 1993), meloxicam (Turck et al., 1995), etc. In continuation of our research on potential biologically active benzothiazine compounds (Siddiqui et al., 2007; Ahmad, Siddiqui, Zia-ur-Rehman et al., 2010), we report the synthesis and crystal structure of the title compound in this article.

In the title compound (Fig. 1), the bond distances and angles agree with the cortresponding bond distances and angles reported in closely related compounds (Siddiqui et al., 2008; Ahmad, Siddiqui, Rizvi et al., 2010). The heterocyclic thiazine ring adopts half chair conformation with atoms S1 and N1 displaced by 0.410 (3) and 0.299 (3) Å on the opposite sides from the mean planes formed by the remaining ring atoms.

The structure is stabilized by intermolecular hydrogen bonds of the types O—H···O and C—H···O; the former result in dimers lying about inversion centers and the later form chains of molecules running along the c-axis (Tab. 1 and Fig. 2). In addition, intramolecular interactions of the types O—H···O and C—H···N are also present consolidating the crystal packing.

Experimental

An aqueous sodium hydroxide solution (1.33 g in 10 ml water) was slowly added to a solution of 3-benzoyl-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxide (5.0 g, 16.6 mmole) in acetone (50 ml). Dimethylsulfate (4.03 g, 32 mmole) was added drop wise and the mixture was stirred for 30 minutes. The contents of the flask were acidified to pH 3.0 by the addition of 5% HCl. White precipitates of the title compound were formed which were collected and washed with excess distilled water. Crystals suitable for crystallographic study were grown from a solution of chloroform/methanol (4:1); yield = 3.5 g, 70%; m.p. = 420-421 K.