1,2-Bis(1,3-benzothia­zol-2-yl)benzene

Guo-wei Wang; Lin-ping Wu; Ling-hua Zhuang; Jin-tang Wang

doi:10.1107/S1600536808042542

. 2008 Dec 20;65(Pt 1):o158. doi: 10.1107/S1600536808042542

1,2-Bis(1,3-benzothiazol-2-yl)benzene

Guo-wei Wang ^a,^*, Lin-ping Wu ^a, Ling-hua Zhuang ^b, Jin-tang Wang ^b

PMCID: PMC2968071 PMID: 21581615

Abstract

The title compound, C₂₀H₁₂N₂S₂, was prepared by the reaction of o-phthalic acid and 2-aminothiophenol under microwave irradation. The phenyl ring, A, and the benzothiazolyl rings, B and C, are planar; the dihedral angles are A/B = 19.9 (11), A/C = 87.8 (3) and B/C = 84.4 (4)°. Weak intermolecular C—H⋯N hydrogen bonds link the molecule, forming zigzag chains parallel to the c axis.

Related literature

For details of the synthesis and applications of benzothiazoles, see: Chakraborti et al. (2004 ▶); Seijas et al. (2007 ▶). For the use of microwave-assisted organic synthesis, see: Kappe & Stadler (2005 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₂₀H₁₂N₂S₂
M _r = 344.44
Monoclinic,
a = 10.748 (2) Å
b = 19.148 (4) Å
c = 8.1840 (16) Å
β = 100.77 (3)°
V = 1654.6 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 293 (2) K
0.30 × 0.20 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.909, T _max = 0.968
3000 measured reflections
3000 independent reflections
1640 reflections with I > 2σ(I)
3 standard reflections every 200 reflections intensity decay: 9%

Refinement

R[F ² > 2σ(F ²)] = 0.069
wR(F ²) = 0.206
S = 1.10
3000 reflections
217 parameters
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808042542/dn2416sup1.cif

e-65-0o158-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808042542/dn2416Isup2.hkl

e-65-0o158-Isup2.hkl^{(147.2KB, 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
C12—H12⋯N2ⁱ	0.93	2.46	3.370 (7)	165

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

supplementary crystallographic information

Comment

Benzothiazole are remarkable heterocyclic ring systems. They have been found to exhibit a wide spectrum of biological activities. They have shown antitumor,antimalarial,and fungicide activity. They are also an important class of industrial chemicals. Many kinds of 2-substituted benzothiazoles are utilized as vulcanization accelators in the manufacture of rubber,as fluorescent brightening agents in textile dyeing,and in the leather industry (Chakraborti et al.,2004; Seijas et al.,2007). There are numerous synthetic methods to produce 2-arylbenzothiazoles. The most important ones include the reaction of o-aminothiophenols with benzoic acids or their derivatives (Chakraborti et al.,2004; Seijas et al.,2007). Microwave-assisted organic synthesis (MAOS) is a powerful technique that is being used more and more to accelerate thermal organic reactions (Kappe & Stadler, 2005). We are focusing on Microwave-assisted synthesis of new products of bisbenzothiazole. We here report the crystal structure of the title compound (I).

The phenyl ring A (C8/C9/C13), benzothiazolyl ring B(C1/C2/C6/C7) and benzothiazolyl ring C(C14/C15/C20) are planar (Fig. 1). The dihedral angles between them are A/B = 19.9°, A/C = 87.8°, B/C = 84.4°, respectively. All bond lengths are within normal ranges (Allen et al., 1987). There are weak intermolecular C—H···N hydrogen bonds whick link the molecule forming zig-zag chains parallel to the c axis .(Table 1, Fig.2).

Experimental

A mixture of 2-aminothiophenol (2.5 g, 20 mmol), 5 ml orthophosphoric acid, 5 g polyphosphoric acid and o-phthalic acid (1.66 g, 10 mmol) in a beakerflask (150 ml) was placed in a domestic microwave oven (0.8 KW, 2450 MHz) and irradiated (micromode, full power) for 4 min(30 s per time). The reaction mixture was cooled to r.t. and washed with aq NaOH (20%, 150 ml), The pH was adjusted to 10, the resulted solide was filtered. Then the crude compound(I) was obtained. It was crystallized from ethanol. Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of methanol. ¹H NMR (DMSO, δ, p.p.m.) 7.35–7.40 (m, 2 H), 7.46–7.51 (m, 2 H), 7.64 (dd,2 H), 7.81 (d, 2 H), 7.95 (dd,2 H), 8.05 (d,2 H).