2-Methyl-12H-benzimidazo[2,1-b][1,3]benzothia­zin-12-one

Zhiming Wang; Bin Yu; Shen Li; Caihong Zou; Xiaoqiang Sun

doi:10.1107/S1600536811050501

. 2011 Nov 30;67(Pt 12):o3506. doi: 10.1107/S1600536811050501

2-Methyl-12H-benzimidazo[2,1-b][1,3]benzothiazin-12-one

Zhiming Wang ^a, Bin Yu ^a, Shen Li ^a, Caihong Zou ^a, Xiaoqiang Sun ^a,^*

PMCID: PMC3239128 PMID: 22199976

Abstract

In the title compound, C₁₅H₁₀N₂OS, prepared by the reaction of 2-iodo-5-methylbenzoyl chloride with 2-mercaptobenzimidazole, the four-membered fused-ring system is essentially planar [maximum deviation from the least-squares plane = 0.137 (6) Å]. The crystal packing is stabilized by weak intermolecular π–π interactions [minimum ring centroid separation = 3.536 (4) Å] and weak C—H⋯π interactions.

Related literature

For general background to imidazo[2,1-b][1,3]thiazinones, see: van der Helm et al. (1987 ▶); Dolbier et al. (1994 ▶); Sekar et al. (2011 ▶).

Experimental

Crystal data

C₁₅H₁₀N₂OS
M _r = 266.31
Orthorhombic,
a = 11.7737 (5) Å
b = 8.1122 (3) Å
c = 26.0694 (10) Å
V = 2489.90 (17) Å³
Z = 8
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 293 K
0.38 × 0.35 × 0.32 mm

Data collection

Agilent Xcalibur Atlas Gemini Ultra CCD diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.911, T _max = 0.924
9905 measured reflections
2277 independent reflections
1826 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.097
S = 1.03
2277 reflections
174 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: OLEX2.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811050501/zs2165sup1.cif

e-67-o3506-sup1.cif^{(16KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811050501/zs2165Isup2.hkl

e-67-o3506-Isup2.hkl^{(112KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811050501/zs2165Isup3.cml

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

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

Cg1 is the centroid of the N1/N2/C9–C11 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯Cg1ⁱ	0.93	2.90	3.765 (3)	156

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported financially by the Priority Academic Program Development of Jiangsu Higher Education Institutions.

supplementary crystallographic information

Comment

Owing to the promising biological activities as antimicrobial agents against bacteria, yeast and fungi, imidazo[2,1-b][1,3]thiazinones have been studied (van der Helm et al., 1987). In the past decades, most of these investigations were carried out with imidazole derivatives (Dolbier et al., 1994; Sekar et al., 2011). We herein present the structure of the title compound C₁₅H₁₀N₂OS, prepared from the reaction of 2-iodo-5-methylbenzoyl chloride with 2-mercaptobenzimidazole.

In the crystal structure, the title compound adopts an essentially planar conformation (Fig. 1), with the maximum atom deviation from the least-squares plane to the four-membered fused-ring system = 0.137 (6) Å]. The dihedral angles between the benzimidazole ring (N1–C15) and the thiazine ring (S1–C9) = 3.18 (5) °, the benzene ring (C2–C7) and the thiazine ring (S1–C9) = 0.38 (6)° and the benzimidazole ring (N1–C15) and the benzene ring (C2–C7) = 3.55 (6)°.

The crystal packing is stabilized by weak intermolecular π–π interactions involving the six-membered aromatic rings: (a) the thiazine ring S1–C9 (ring 1) and the benzene ring C10–C15ⁱ (ring 2) of the benzimazole moiety [ring centroid separation = 3.628 (8) Å: symmetry code (i) -x + 1, -y + 1, -z + 1]; (b) between the benzene ring C2–C7 (ring 3) and ring C2–C7ⁱ = 3.817 (6) Å; (c) between ring 3···and ring 2ⁱ = 3.536 (4) Å. There are also C—H···π interactions present.

Experimental

An oven-dried Schlenk tube was charged with a magnetic stirring bar, CuI (0.05 mmol), 1,10-phenanthroline (0.10 mmol), Cs₂CO₃ (0.50 mmol), and 2-mercaptobenzimidazole. The Schlenk tube was capped, and then evacuated and backfilled with N₂ (3 times), then under a positive pressure of N₂, a solution of 2-iodo-5-methylbenzoyl chloride (0.75 mmol) in toluene (2 ml, freshly distilled from sodium) was added dropwise via syringe, and the mixture was pre-stirred for 1 h at room temperature. The reaction mixture was then stirred at 100 °C. After the reaction was completed, the mixture was cooled to room temperature, passed through Celite and rinsed with 30 ml of CH₂Cl₂. The combined filtrate was concentrated and purified by flash chromatography to give a yellow solid (93% yield). Single crystals of the title compound suitable for X-ray diffraction were obtained by evaporation of a petroleum ether–chloroform solution.