3,3-Dibromo-1-ethyl-1H-2,1-benzo­thiazin-4(3H)-one 2,2-dioxide

Muhammad Shafiq; M Nawaz Tahir; Islam Ullah Khan; Saeed Ahmad; Waseeq Ahmad Siddiqui

doi:10.1107/S1600536808017510

. 2008 Jun 13;64(Pt 7):o1270. doi: 10.1107/S1600536808017510

3,3-Dibromo-1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide

Muhammad Shafiq ^a, M Nawaz Tahir ^b,^*, Islam Ullah Khan ^a, Saeed Ahmad ^c, Waseeq Ahmad Siddiqui ^d

PMCID: PMC2961809 PMID: 21202903

Abstract

In the molecule of the title compound, C₁₀H₉Br₂NO₃S, the S atom is four-coordinated in distorted tetrahedral configuration. The heterocyclic thiazine ring adopts a twist conformation. An intramolecular C—H⋯O hydrogen bond results in the formation of a non-planar five-membered ring. In the crystal structure, intermolecular C—H⋯O hydrogen bonds link the molecules into infinite chains along the c axis.

Related literature

For related literature, see: Franzén (2000 ▶); Misu & Togo (2003 ▶); Shafiq et al. (2008 ▶); Tahir et al. (2008 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₀H₉Br₂NO₃S
M _r = 383.06
Monoclinic,
a = 7.7979 (5) Å
b = 11.9645 (7) Å
c = 13.1231 (8) Å
β = 95.374 (3)°
V = 1218.98 (13) Å³
Z = 4
Mo Kα radiation
μ = 6.82 mm⁻¹
T = 296 (2) K
0.15 × 0.12 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.400, T _max = 0.508
14754 measured reflections
3281 independent reflections
1708 reflections with I > 2σ(I)
R _int = 0.059

Refinement

R[F ² > 2σ(F ²)] = 0.066
wR(F ²) = 0.221
S = 1.02
3281 reflections
154 parameters
H-atom parameters constrained
Δρ_max = 1.27 e Å⁻³
Δρ_min = −1.61 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007 ▶); 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 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808017510/hk2472sup1.cif

e-64-o1270-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808017510/hk2472Isup2.hkl

e-64-o1270-Isup2.hkl^{(97.8KB, 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
C2—H2⋯O1ⁱ	0.93	2.52	3.390 (10)	157
C9—H9A⋯O1	0.97	2.38	2.876 (11)	111

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Symmetry code: (i) Inline graphic .

Acknowledgments

Muhammad Shafiq greatfully acknowledges the Higher Education Commision, Islamabad, Pakistan, for providing a Scholarship under the Indigenous PhD Program.

supplementary crystallographic information

Comment

The synthesis of heterocyclic system is of continuing interest because a large number of biologically active molecules contain heterocyclic rings (Franzén, 2000). 2,1-Benzothiazine is a relatively unexplored ring system with respect to both its synthesis and biological activity, in which it belongs to an important heterocyclic class of compounds, although it finds a number of applications in medicinal chemistry. The derivatives of 2,1-benzothiazine are used as drugs for heart diseases and also show lipoxygenase inhibition activity (Misu & Togo, 2003). Recently we have reported the crystal structures of 1-ethyl-1H -2,1-benzothiazin-4(3H) one 2,2-dioxide, (II) (Shafiq et al., 2008) and 1-methyl-1H-2,1-benzothiazin-4(3H) one 2,2-dioxide, (III) (Tahir et al., 2008), in which they contain the same heterocyclic ring. We report herein the syntesis and crystal structure of the title compound, (I), which is obtained from the bromination of (II).

In the molecule of (I) (Fig. 1), the bond lengths and angles are within normal ranges, which are comparable with the corresponding values in (II). The S1-N1 [1.617 (6) Å], S1-C8 [1.792 (8) Å] and C7-C8 [1.540 (11) Å] bonds in (I) are reported as 1.6405 (15), 1.750 (2) and 1.510 (3) Å, respectively, in (II). The S atom is four-coordinated in distorted tetrahedral configuration (Table 1) by one N and one C atoms of the heterocyclic ring and two O atoms. Ring A (C1-C6) is, of course, planar, and it is oriented with respect to (S1/O1/O2) and (C8/Br1/Br2) planes at dihedral angles of 78.44 (32)° and 77.79 (28)°, respectively. Ring B (S1/N1/C1/C6-C8) adopts twisted conformation, having total puckering amplitude, Q_T, of 0.763 (2) Å (Cremer & Pople, 1975). The intra- molecular C-H···O hydrogen bond (Table 2) results in the formation of a non-planar five-membered ring C (O1/S1/N1/C9/H9A).

In the crystal structure, intermolecular C-H···O hydrogen bonds (Table 2) link the molecules into infinine chains along the c axis (Fig. 2), in which they may be effective in the stabilization of the structure.

Experimental

Compound (I) was prepared by the reaction of (II) (34.0 mg, 0.15 mmol), N-bromosuccinimide (57.0 mg, 0.32 mmol) and dibenzoyl peroxide (2.1 mg, 0.009 mmol) in CCl₄ (8 ml) by heating under reflux for 2 h. Crystals suitable for X-ray analysis were obtained by evaporating the solvent slowly at room temperature for about 7 d (m.p. 394-395 K).