(Z)-2-(4-Chloro­benzyl­idene)benzo[d]thia­zolo[3,2-a]imidazol-3(2H)-one

Hoong-Kun Fun; Suchada Chantrapromma; Hatem A Abdel-Aziz

doi:10.1107/S1600536812015516

. 2012 Apr 18;68(Pt 5):o1393–o1394. doi: 10.1107/S1600536812015516

(Z)-2-(4-Chlorobenzylidene)benzo[d]thiazolo[3,2-a]imidazol-3(2H)-one

Hoong-Kun Fun ^a,^*,^‡, Suchada Chantrapromma ^b,^§, Hatem A Abdel-Aziz ^c

PMCID: PMC3344520 PMID: 22590282

Abstract

The molecule of the title compound, C₁₆H₉ClN₂OS, is approximately planar, the dihedral angle between the thiazolo[3,2-a]benzimidazole ring system and the 4-chlorophenyl ring being 2.10 (5)°. An intramolecular C—H⋯S interaction generates an S(6) ring motif. In the crystal, molecules are stacked into columns along the b axis by π–π interactions with centroid–centroid distances of 3.6495 (7)–3.9546 (8) Å.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For background to and the biological activity of thiazolo[3,2-a]benzimidazoles, see: Abdel-Aziz, El-Zahabi & Dawood (2010 ▶); Abdel-Aziz, Hamdy et al. (2007 ▶, 2008 ▶); Abdel-Aziz, Saleh & El-Zahabi (2010 ▶); Al-Rashood & Abdel-Aziz (2010 ▶); Chimirri et al. (1988 ▶); Farag et al. (2011 ▶); Hamdy et al. (2007 ▶); Mavrova et al. (2005 ▶). For the stability of the temperature controller, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₆H₉ClN₂OS
M _r = 312.77
Triclinic,
a = 7.0182 (4) Å
b = 7.3443 (4) Å
c = 13.7142 (8) Å
α = 91.742 (1)°
β = 100.836 (1)°
γ = 112.878 (1)°
V = 635.47 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.46 mm⁻¹
T = 100 K
0.37 × 0.18 × 0.06 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.848, T _max = 0.973
14145 measured reflections
3660 independent reflections
3233 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.082
S = 1.05
3660 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.56 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812015516/is5117sup1.cif

e-68-o1393-sup1.cif^{(23.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812015516/is5117Isup2.hkl

e-68-o1393-Isup2.hkl^{(179.4KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812015516/is5117Isup3.cml

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
C16—H16A⋯S1	0.93	2.50	3.2161 (13)	133

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Acknowledgments

HAAA thanks the Deanship of Scientific Research and the Research Center, College of Pharmacy, King Saud University. HKF and SC thank Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

There are considerable interest in the chemistry of thiazolo[3,2-a]benzimidazoles and their unique pharmaceutical and medicinal applications have been reported. These activities including antibacterial, antifungal, anti-inflammatory, antiulcer, antiviral, anthelmintic and anticancer properties (Al-Rashood et al., 2010; Chimirri et al., 1988). The parasitological study in vitro has also shown that the analogs of the title compound exhibited higher activity than albendazole against T. spiralis (Mavrova et al., 2005). These considerable biological activities as well as in continuation of our interests in the chemistry and biological activities of these compounds (Abdel-Aziz, Hamdy et al., 2007, 2008; Abdel-Aziz, Saleh & El-Zahabi, 2010; Farag et al., 2011; Hamdy et al., 2007) have lead us to synthesize and present the X-ray structural analysis of the title compound (I).

In the molecular structure of (I), C₁₄H₁₁ClN₄O₄, the thiazolo[3,2-a]benzimidazole ring system is planar with an r.m.s. deviation 0.019 (12) Å for the thirteen non H-atoms (C1–C9/N1/N2/O1/S1) and the 4-chlorobenzilidene unit is also planar with an r.m.s deviation 0.002 (12) Å for the eight non H-atoms (C10–C16/Cl1). The dihedral between the mean plane through the thiazolo[3,2-a]benzimidazole ring system and 4-chlorophenyl ring is 2.10 (5)°. An intramolecular C—H···S weak interaction (Fig. 1 and Table 1) generates an S(6) ring motif (Bernstein et al., 1995) which help to stabilize the planarity of the molecule. The bond distances agree with the literature values (Allen et al., 1987).

In the crystal packing (Fig. 2), the molecules are stacked into column along the b axis by π–π interactions with the distances of Cg1···Cg1ⁱ = 3.8297 (7) Å, Cg2···Cg4ⁱⁱ = 3.9545 (8) Å, Cg3···Cg4ⁱ = 3.7691 (8) Å and Cg3···Cg4ⁱⁱ = 3.6495 (7) Å [symmetry codes: (i) 1-x, 1-y, -z; (ii) 1-x, -y, -z]. Cg1, Cg2, Cg3 and Cg4 are the centroids of S1/C1/N2/C8/C9, C1/C2/C7/N1/N2, C2–C7 and C11–C16 rings, respectively.

Experimental

The one-pot synthesis of the title compound was carried out by a cyclocondensation of 2-mercaptobenzimidazole, chloroacetic acid, 4-chloro benzaldehyde, acetic anhydride and glacial acetic acid in the presence of sodium acetate to afford the title compound (Mavrova et al., 2005; Abdel-Aziz, El-Zahabi & Dawood, 2010). Yellow needle-shaped single crystals of the title compound suitable for x-ray structure determination were recrystalized from ethanol by slow evaporation of the solvent at room temperature over several days.