3-Bromo-2-[4-(methyl­sulfan­yl)phen­yl]-5,6,7,8-tetra­hydro-1,3-benzo­thia­zolo[3,2-a]imidazole

Alexander S Bunev; Elena V Sukhonosova; Vladimir E Statsyuk; Gennady I Ostapenko; Victor N Khrustalev

doi:10.1107/S1600536814008976

. 2014 Apr 26;70(Pt 5):o596–o597. doi: 10.1107/S1600536814008976

3-Bromo-2-[4-(methylsulfanyl)phenyl]-5,6,7,8-tetrahydro-1,3-benzothiazolo[3,2-a]imidazole

Alexander S Bunev ^a,^*, Elena V Sukhonosova ^b, Vladimir E Statsyuk ^a, Gennady I Ostapenko ^a, Victor N Khrustalev ^c

PMCID: PMC4011264 PMID: 24860393

Abstract

In the title molecule, C₁₆H₁₅BrN₂S₂, the central imidazo[2,1-b]thiazole fragment is almost planar (r.m.s. deviation = 0.012 Å), and the fused 5,6,7,8-tetrahydrobenzene ring adopts an unsymmetrical half-chair conformation. The dihedral angle between the imidazo[2,1-b]thiazole and benzene planes is 18.25 (4)°. The terminal methylsulfanyl substituent lies practically within the benzene plane [the dihedral angle between the corresponding planes is 7.20 (10)°] and is turned toward the C—Br bond. In the crystal, molecules form infinite chains along [100] via secondary Br⋯N interactions [3.1861 (16) Å]. The chains are arranged at van der Waals distances.

Related literature

For applications of imidazo[2,1-b][1,3]benzothiazoles, see: Ager et al. (1988 ▶); Sanfilippo et al. (1988 ▶); Barchéchath et al. (2005 ▶); Andreani et al. (2008 ▶); Chao et al. (2009 ▶); Kumbhare et al. (2011 ▶); Chandak et al. (2013 ▶). For the crystal structures of related compounds, see: Landreau et al. (2002 ▶); Adib et al. (2008 ▶); Fun, Asik et al. (2011 ▶); Fun, Hemamalini et al. (2011 ▶); Ghabbour et al. (2012 ▶); Bunev et al. (2013 ▶, 2014 ▶).

Experimental

Crystal data

C₁₆H₁₅BrN₂S₂
M _r = 379.34
Triclinic,
a = 7.3132 (3) Å
b = 7.5663 (3) Å
c = 14.4543 (7) Å
α = 95.033 (1)°
β = 97.188 (1)°
γ = 101.938 (1)°
V = 771.03 (6) Å³
Z = 2
Mo Kα radiation
μ = 2.93 mm⁻¹
T = 120 K
0.15 × 0.10 × 0.10 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T _min = 0.668, T _max = 0.758
10352 measured reflections
4508 independent reflections
3927 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.073
S = 1.05
4508 reflections
191 parameters
H-atom parameters constrained
Δρ_max = 0.67 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814008976/rk2426sup1.cif

e-70-0o596-sup1.cif^{(24.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814008976/rk2426Isup2.hkl

e-70-0o596-Isup2.hkl^{(220.8KB, hkl)}

Click here for additional data file.^{(5.9KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814008976/rk2426Isup3.cml

CCDC reference: 998505

Additional supporting information: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors are grateful to the Ministry of Education and Science of the Russian Federation (State program No. 426).

supplementary crystallographic information

1. Comment

Imidazo[2,1–b][1,3]benzothiazole are of great interest due to their biological properties. These compounds and their derivatives demonstrate the antitumor (Andreani et al., 2008), antiallergic (Ager et al., 1988), anesthetic (Sanfilippo et al., 1988) and anti–cancer (Kumbhare et al., 2011) activities as well as the inhibition activity of apoptosis in testiculargerm cells (Chandak et al., 2013), lymphocytes (Barchéchath et al., 2005), and FMS–like tyrosine kinase–3 (FLT3) (Chao et al., 2009).

In this work, a new halogensubstituted 5,6,7,8–tetrahydrobenzo[d]imidazo[2,1–b]thiazole, C₁₆H₁₅BrN₂S₂, I, was prepared by the reaction of 5,6,7,8–tetrahydrobenzo[d]imidazo[2,1–b]thiazole with bromine at room temperature (Fig. 1), and its structure was unambiguously established by the X–ray diffraction study (Fig. 2).

In the title molecule (I) the central imidazo[2,1–b]thiazole fragment is almost planar (r.m.s. deviation = 0.012 Å), and the fused 5,6,7,8-tetrahydrobenzene ring adopts an unsymmetrical half–chair conformation (the C6 and C7 carbon atoms are out of the plane passed through the other atoms of the ring by -0.246 (2) and 0.508 (2) Å, respectively). The bond lengths and angles within the molecule of I are in a good agreement with those found in the related compounds (Landreau et al., 2002; Adib et al., 2008; Fun, Asik et al., 2011; Fun, Hemamalini et al., 2011; Ghabbour et al., 2012; Bunev et al., 2013, 2014). The dihedral angle between the imidazo[2,1–b]thiazole and benzene planes is 18.25 (4)°. The terminal methylthio substituent lies practically within the benzene plane (the dihedral angle between the corresponding planes is 7.20 (10)°) and is turned toward the C—Br bond.

In the crystal, the molecules of I form infinite chains along [100] by intermolecular secondary Br1···N1ⁱ interactions (3.1861 (16) Å) (Fig. 3). The chains are arranged at van der Waals distances. Symmetry code: (i) 1 + x, y, z.

2. Experimental

A solution of bromine (139 µL, 430.4 mg, 2.69 mmol) in dry CHCl₃ (10 mL) was added to a solutions 2–(4–(methylthio)phenyl)–5,6,7,8–tetrahydrobenzo[d]imidazo[2,1–b]thiazole (808.3 mg, 2.69 mmol) in dry CHCl₃ (30 mL). The reaction mixture was stirred at room temperature for 3 h. the solvent was evaporated from the reaction mixture on rotavapor. The crude product was diluted with 5% solution Na₂CO₃ in water (25 mL). The precipitate was filtered and crystallized from DMF. Yield is 75%. The single–crystal of the product I was obtained by slow crystallization from DMF. M.p. = 439–441 K. IR (KBr), ν/cm^-1: 3131, 3073, 1580, 1523, 1501, 1337, 1144, 815, 714. ¹H NMR (600 MHz, DMSO–d₆, 304 K): 7.63 (d, 2H, J = 8.9), 7.54 (d, 2H, J = 8.9), 3.39–3.33 (m, 2H), 3.02–2.96 (m, 2H), 2.45 (s, 3H), 1.91–1.81 (m, 4H). Anal. Calcd for C₁₆H₁₅BrN₂S: C, 50.66; H, 3.99. Found: C, 50.57; H, 4.08.