Diethyl 3,4-dimethyl­thieno[2,3-b]thio­phene-2,5-dicarboxyl­ate

Mehmet Akkurt; Alan R Kennedy; Sabry H H Younes; Shaaban K Mohamed; Gary J Miller

doi:10.1107/S160053681204593X

. 2012 Nov 10;68(Pt 12):o3332–o3333. doi: 10.1107/S160053681204593X

Diethyl 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylate

Mehmet Akkurt ^a,^*, Alan R Kennedy ^b,^*, Sabry H H Younes ^c, Shaaban K Mohamed ^d,^e, Gary J Miller ^f,^*

PMCID: PMC3588935 PMID: 23476171

Abstract

In the title compound, C₁₄H₁₆O₄S₂, the thieno[2,3-b]thiophene ring systems are planar [maximum deviation = 0.008 (2) Å]. The molecular conformation is stabilized by intramolecular C—H⋯O hydrogen bonds, while the crystal packing is stabilized by C—H⋯O, C—H⋯π and π–π stacking [centroid–centroid distance = 3.6605 (14) Å] interactions, which lead to supramolecular layers in the ab plane.

Related literature

For the use of thienthiophenes as versatile precursors for the synthesis of various heterocycles, see: Mabkhot et al. (2010 ▶, 2012 ▶); Litvinov (2005 ▶). For their industrial applications, see: Lee & Sotzing (2001 ▶); Heeney et al. (2005 ▶); Gather et al. (2008 ▶); He et al. (2009 ▶). For pharmaceutical values of thieno[2,3-b]thiophenes, see: Jarak et al. (2006 ▶); Egbertson et al. (1999 ▶). For bond lengths and bond angles in similar compounds, see: Umadevi et al. (2009 ▶); Gunasekaran et al. (2009 ▶); Wang et al. (2008 ▶). For the synthesis of the title compound, see: Comel & Kirsch (2001a ▶,b ▶). For graph-set descriptions of hydrogen-bond ring motifs, see: Bernstein et al. (1995 ▶). graphic file with name e-68-o3332-scheme1.jpg

Experimental

Crystal data

C₁₄H₁₆O₄S₂
M _r = 312.39
Triclinic,
a = 7.3497 (3) Å
b = 8.4720 (4) Å
c = 12.8629 (5) Å
α = 102.770 (3)°
β = 99.545 (3)°
γ = 107.779 (4)°
V = 719.96 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.38 mm⁻¹
T = 123 K
0.30 × 0.08 × 0.06 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.966, T _max = 1.000
6901 measured reflections
3486 independent reflections
2661 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.106
S = 1.04
3486 reflections
185 parameters
H-atom parameters constrained
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 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: ORTEP-3 for Windows (Farrugia, 2012 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶) and PLATON.

Supplementary Material

Click here for additional data file.^{(24.5KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681204593X/tk5168sup1.cif

e-68-o3332-sup1.cif^{(24.5KB, cif)}

Click here for additional data file.^{(167.5KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681204593X/tk5168Isup2.hkl

e-68-o3332-Isup2.hkl^{(167.5KB, hkl)}

Click here for additional data file.^{(5.7KB, cml)}

Supplementary material file. DOI: 10.1107/S160053681204593X/tk5168Isup3.cml

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

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

Cg2 is the centroid of the S2/C1–C4 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7A⋯O1	0.98	2.22	2.980 (3)	133
C8—H8A⋯O3	0.98	2.23	2.909 (3)	125
C11—H11A⋯O4ⁱ	0.98	2.53	3.471 (3)	161
C8—H8C⋯Cg2ⁱⁱ	0.98	2.74	3.578 (3)	144

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

SHHY thanks Sohag University for facilitating this collaborative project with Manchester Metropolitan University. Our gratitude is extended to Erciyes University and the University of Strathclyde for supporting this study.

supplementary crystallographic information

Comment

Thienothiophene compounds are a great class of sulfur heterocyclic chemistry due their utilities in various applications in industrial and medicinal fields. They have wide variety applications in optical and electronic systems (Gather et al., 2008; He et al., 2009). Besides, thieno[2,3-b]thiophenes showed useful reactivities as co-polymerization agents (Lee & Sotzing, 2001) and as semiconductors (Heeney et al., 2005). They have been developed and tested as potential antitumor, antiviral, antiglaucoma drugs, antiproliferation agents, or as inhibitors of platelet aggregation (Jarak et al., 2006; Egbertson et al., 1999). In addition, thienothiophenes have been used as versatile precursors for synthesis of various heterocycles (Mabkhot et al., 2012, Mabkhot et al., 2010; Litvinov, 2005). In view of such important applications, we herein report the crystal structure determination of the title compound (I) to investigate the relationship between its structure and antibacterial activity.

In the title compound, C₁₄H₁₆O₄S₂, the thieno[2,3-b]thiophene ring systems are planar with a maximum deviation of 0.008 (2) Å for C2. The values of the bond lengths and bond angles in (I) are in the normal range and comparable to those reported for the similar compounds (Umadevi et al., 2009; Gunasekaran et al., 2009; Wang et al., 2008). The O1–C9–C2–S2, O2–C9–C2–S2, O3–C12–C6–S1 and O4–C12–C6–S1 bond angles are 175.95 (19), -4.8 (3), 176.14 (16) and 4.0 (3)°, respectively.

The intramolecular C7—H7A···O1 and C8—H8A···O3 interactions form six- membered rings, producing S(6) ring motif (Table 1; Bernstein et al., 1995). In the crystal, the molecules are linked by intermolecular C—H···O hydrogen bonds (Table 1, Fig. 2), and are further consolidated by C—H···π interactions and π-π stacking [Cg1···Cg1(-x, 1 - y, 1 - z) = 3.6605 (14) Å; where Cg1 is a centroid of the S1/C1/C4–C6 ring] interactions.

Experimental

The title compound was prepared according to the reported method in literature (Comel & Kirsch, 2001a,b). Single crystals suitable for X-ray analysis were grown in an ethanol solution of (I) at room temperature over 24 h. M.pt: 413 K.