organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

6-Nitro-2,3-bis­­(thio­phen-2-yl)quinoxaline

aDepartment of Chemistry & Biochemistry, Central Connecticut State University, 1619 Stanley Street, New Britain, CT 06053, USA
*Correspondence e-mail: crundwellg@ccsu.edu

Edited by K. Fejfarova, Institute of Biotechnology CAS, Czech Republic (Received 12 February 2020; accepted 12 February 2020; online 14 February 2020)

The title compound, C16H9N3O2S2, was synthesized via a condensation reaction in refluxing acetic acid. One thienyl ring is nearly coplanar with the quinoxaline unit [dihedral angle = 3.29 (9)°], the other makes an angle of 83.96 (4)°.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

6-Nitro-2,3-bis­(thio­phen-2-yl)quinoxaline crystallizes in space group P21/c. All bond lengths and angles are within expected values. Unlike in the related mol­ecule 5-nitro-2,3-bis­(thio­phen-2-yl)quinoxaline (de Freitas et al., 2020[Freitas, J. F. de, Brown, S., Oberndorfer, J. S. & Crundwell, G. (2020). IUCrData, 5, x200196.]), one thienyl ring and the nitro group in the title compound are nearly coplanar with the quinoxaline moiety. The nitro group makes a dihedral angle of 7.76 (14)° with respect to the mean plane of the quinoxaline unit. A survey of the literature on other 6-nitro­quinoxalines reveals that the nitro group is routinely nearly coplanar. The two thienyl rings make dihedral angles of 83.96 (4) and 3.29 (9)°, for the rings with S1 and S2 respectively, with the mean plane of the quinoxaline unit. The coplanar thienyl ring sulfur atom is closer in proximity to the quinoxaline nitro­gen atom, in the trans arrangement of Du & Zhao (2003[Du, M. & Zhao, X.-J. (2003). Acta Cryst. C59, o403-o405.]). The other thienyl ring is nearly perpendicular to the plane of the quinoxaline; barely adopting the aforementioned authors cis arrangement. There are no inter­molecular inter­actions of consequence. An ORTEP view is shown in Fig. 1[link] and a view of the unit cell along (010) is shown in Fig. 2[link].

[Figure 1]
Figure 1
A view of 6-nitro-2,3-bis­(thio­phen-2-yl)quinoxaline (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]). Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2]
Figure 2
A view of the unit cell of 6-nitro-2,3-bis­(thio­phen-2-yl)quinoxaline along (010).

Synthesis and crystallization

2-Thio­phene­carboxaldehyde was condensed to 2,2′-thenoin (Crundwell et al., 2002[Crundwell, G., Meskill, T., Sayers, D. & Kantardjieff, K. (2002). Acta Cryst. E58, o666-o667.]) followed by oxidation to 2,2′-thenil (Crundwell et al., 2003[Crundwell, G., Sullivan, J., Pelto, R. & Kantardjieff, K. (2003). J. Chem. Cryst, 33, 239-244.]). The nitro­phenyl­enedi­amines were used as purchased from Sigma–Aldrich.

In a 100 ml round-bottom flask, 2.22 g of 2,2′-thenil (10.0 mmol) and 1.52 g of 4-nitro-1,2-phenyl­enedi­amine were added to 50 ml of concentrated acetic acid. The solution was refluxed with stirring for 18 h. The solution was cooled to room temperature and neutralized with 6 M NaOH. The solution was again cooled then filtered. The resulting solid was filtered and washed with cold water then dried. The yield of the yellow product was 3.10 g (92%), m.p. 474 K. 1H NMR (CDCl3, 300 MHz): δ = 7.10 (m, 2H), 7.43 (m, 2H), 7.61 (m, 2H), 8.20 (d, 1H), 8.49 (dd, 1H), 8.98 (d, 1H); 13C NMR (CDCl3, 300 MHz): δ = 123.4, 125.2, 127.8, 127.9, 130.2, 130.3, 130.7, 139.3, 140.5, 140.8, 143.0, 147.8, 148.7, 149.3.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1[link].

Table 1
Experimental details

Crystal data
Chemical formula C16H9N3O2S2
Mr 339.38
Crystal system, space group Monoclinic, P21/c
Temperature (K) 293
a, b, c (Å) 11.7649 (4), 5.3386 (2), 24.3536 (8)
β (°) 105.610 (3)
V3) 1473.18 (9)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.37
Crystal size (mm) 0.40 × 0.30 × 0.18
 
Data collection
Diffractometer Oxford Diffraction Xcalibur, Sapphire3
Absorption correction Multi-scan (CrysAlis PRO; Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD, CrysAlis RED and CrysAlis PRO. Oxford Diffraction, Yarnton, England.])
Tmin, Tmax 0.871, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 12501, 5931, 3620
Rint 0.020
(sin θ/λ)max−1) 0.802
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.062, 0.199, 1.06
No. of reflections 5931
No. of parameters 208
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.51, −0.33
Computer programs: CrysAlis CCD and CrysAlis RED (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD, CrysAlis RED and CrysAlis PRO. Oxford Diffraction, Yarnton, England.]), SHELXS2014 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and OLEX2 (Bourhis et al., 2015[Bourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59-75.]).

Structural data


Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: OLEX2 (Bourhis et al., 2015).

6-Nitro-2,3-bis(thiophen-2-yl)quinoxaline top
Crystal data top
C16H9N3O2S2Dx = 1.530 Mg m3
Mr = 339.38Melting point: 474 K
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 11.7649 (4) ÅCell parameters from 4982 reflections
b = 5.3386 (2) Åθ = 4.2–34.7°
c = 24.3536 (8) ŵ = 0.37 mm1
β = 105.610 (3)°T = 293 K
V = 1473.18 (9) Å3Block, yellow
Z = 40.40 × 0.30 × 0.18 mm
F(000) = 696
Data collection top
Oxford Diffraction Xcalibur, Sapphire3
diffractometer
5931 independent reflections
Radiation source: fine-focus sealed tube3620 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.020
phi and ω scansθmax = 34.7°, θmin = 4.2°
Absorption correction: multi-scan
(CrysAlisPro; Oxford Diffraction, 2009)
h = 1818
Tmin = 0.871, Tmax = 1.000k = 87
12501 measured reflectionsl = 3638
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.062Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.199H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0958P)2 + 0.397P]
where P = (Fo2 + 2Fc2)/3
5931 reflections(Δ/σ)max = 0.001
208 parametersΔρmax = 0.51 e Å3
0 restraintsΔρmin = 0.33 e Å3
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

H atoms were included in calculated positions with C-H distances of 0.93 Å and were included in the refinement in riding motion approximation with Uiso = 1.2 of the carrier atom.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
S10.16791 (7)0.82603 (13)0.52719 (3)0.0622 (2)
S20.02258 (6)1.15002 (14)0.31003 (3)0.0592 (2)
O10.30694 (18)0.1759 (4)0.20797 (8)0.0669 (5)
O20.43910 (18)0.0612 (4)0.26181 (9)0.0663 (5)
N20.20929 (14)0.7957 (3)0.33911 (7)0.0357 (3)
N10.36211 (14)0.6752 (3)0.44590 (7)0.0369 (3)
N30.37406 (17)0.1200 (4)0.25404 (8)0.0463 (4)
C10.27918 (15)0.8444 (4)0.44089 (8)0.0328 (4)
C20.20193 (15)0.9143 (3)0.38578 (7)0.0323 (3)
C30.29042 (16)0.6090 (3)0.34485 (8)0.0322 (3)
C40.29411 (17)0.4671 (4)0.29649 (8)0.0373 (4)
H40.24280.50080.26090.045*
C50.37543 (17)0.2785 (4)0.30344 (8)0.0361 (4)
C60.45704 (19)0.2266 (4)0.35510 (9)0.0445 (5)
H60.51240.09980.35760.053*
C70.45498 (19)0.3639 (4)0.40225 (9)0.0442 (5)
H70.50940.33180.43700.053*
C80.37005 (16)0.5542 (4)0.39796 (8)0.0343 (4)
C90.26743 (17)0.9512 (4)0.49523 (8)0.0369 (4)
C100.3322 (2)1.1441 (5)0.52755 (8)0.0452 (5)
H100.39191.23360.51790.054*
C110.2935 (2)1.1845 (5)0.57763 (9)0.0529 (6)
H110.32491.30840.60420.063*
C120.2088 (2)1.0296 (5)0.58287 (10)0.0567 (6)
H120.17561.03200.61350.068*
C130.11360 (16)1.1131 (4)0.37766 (8)0.0351 (4)
C140.08780 (17)1.2923 (4)0.41567 (9)0.0380 (4)
H140.12661.30510.45420.046*
C150.0063 (2)1.4494 (5)0.38591 (12)0.0545 (6)
H150.03631.57850.40350.065*
C160.0479 (2)1.3957 (5)0.33041 (13)0.0607 (7)
H160.10891.48360.30570.073*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0796 (5)0.0583 (4)0.0622 (4)0.0135 (3)0.0425 (3)0.0078 (3)
S20.0561 (4)0.0676 (4)0.0461 (3)0.0207 (3)0.0002 (2)0.0051 (3)
O10.0714 (12)0.0817 (14)0.0453 (10)0.0018 (10)0.0120 (8)0.0174 (9)
O20.0820 (13)0.0516 (10)0.0741 (12)0.0145 (10)0.0364 (10)0.0087 (9)
N20.0348 (7)0.0401 (8)0.0312 (7)0.0049 (6)0.0069 (6)0.0012 (6)
N10.0352 (7)0.0417 (9)0.0318 (8)0.0048 (7)0.0057 (6)0.0023 (6)
N30.0508 (10)0.0464 (10)0.0482 (10)0.0082 (8)0.0248 (8)0.0092 (8)
C10.0307 (8)0.0359 (9)0.0317 (8)0.0016 (7)0.0080 (6)0.0030 (7)
C20.0301 (8)0.0337 (8)0.0330 (8)0.0012 (7)0.0083 (6)0.0026 (7)
C30.0313 (8)0.0343 (8)0.0313 (8)0.0004 (7)0.0091 (6)0.0021 (7)
C40.0376 (9)0.0420 (10)0.0314 (8)0.0030 (8)0.0075 (7)0.0020 (7)
C50.0374 (9)0.0363 (9)0.0381 (9)0.0019 (7)0.0164 (7)0.0034 (7)
C60.0410 (10)0.0443 (11)0.0481 (11)0.0107 (9)0.0120 (8)0.0010 (9)
C70.0389 (9)0.0520 (12)0.0389 (10)0.0155 (9)0.0056 (7)0.0039 (9)
C80.0304 (8)0.0392 (9)0.0325 (8)0.0026 (7)0.0070 (6)0.0023 (7)
C90.0382 (9)0.0409 (10)0.0318 (9)0.0066 (8)0.0097 (7)0.0045 (7)
C100.0478 (11)0.0561 (13)0.0310 (9)0.0003 (10)0.0091 (8)0.0035 (8)
C110.0652 (14)0.0565 (14)0.0345 (11)0.0066 (12)0.0091 (9)0.0050 (9)
C120.0774 (17)0.0574 (14)0.0433 (12)0.0127 (13)0.0302 (11)0.0004 (10)
C130.0317 (8)0.0354 (9)0.0374 (9)0.0026 (7)0.0082 (7)0.0032 (7)
C140.0367 (9)0.0332 (9)0.0433 (10)0.0069 (7)0.0092 (7)0.0039 (7)
C150.0541 (13)0.0411 (12)0.0739 (17)0.0140 (10)0.0271 (12)0.0075 (11)
C160.0462 (12)0.0614 (15)0.0714 (17)0.0211 (11)0.0103 (11)0.0219 (13)
Geometric parameters (Å, º) top
S1—C91.707 (2)C5—C61.390 (3)
S1—C121.703 (3)C6—H60.9300
S2—C131.7171 (19)C6—C71.368 (3)
S2—C161.696 (3)C7—H70.9300
O1—N31.223 (3)C7—C81.409 (3)
O2—N31.216 (3)C9—C101.392 (3)
N2—C21.324 (2)C10—H100.9300
N2—C31.361 (2)C10—C111.428 (3)
N1—C11.311 (2)C11—H110.9300
N1—C81.359 (2)C11—C121.327 (4)
N3—C51.467 (3)C12—H120.9300
C1—C21.453 (2)C13—C141.420 (3)
C1—C91.481 (3)C14—H140.9300
C2—C131.461 (3)C14—C151.422 (3)
C3—C41.411 (3)C15—H150.9300
C3—C81.408 (2)C15—C161.339 (4)
C4—H40.9300C16—H160.9300
C4—C51.368 (3)
C12—S1—C991.82 (12)N1—C8—C3120.51 (17)
C16—S2—C1392.06 (12)N1—C8—C7119.36 (16)
C2—N2—C3117.91 (15)C3—C8—C7120.06 (17)
C1—N1—C8117.97 (16)C1—C9—S1119.81 (15)
O1—N3—C5118.3 (2)C10—C9—S1111.71 (16)
O2—N3—O1124.1 (2)C10—C9—C1128.42 (19)
O2—N3—C5117.62 (19)C9—C10—H10125.0
N1—C1—C2121.85 (17)C9—C10—C11110.0 (2)
N1—C1—C9115.35 (16)C11—C10—H10125.0
C2—C1—C9122.76 (16)C10—C11—H11122.9
N2—C2—C1120.08 (16)C12—C11—C10114.1 (2)
N2—C2—C13116.08 (16)C12—C11—H11122.9
C1—C2—C13123.84 (16)S1—C12—H12123.8
N2—C3—C4119.05 (16)C11—C12—S1112.30 (18)
N2—C3—C8121.41 (17)C11—C12—H12123.8
C8—C3—C4119.54 (17)C2—C13—S2116.76 (14)
C3—C4—H4121.0C14—C13—S2111.13 (14)
C5—C4—C3118.00 (17)C14—C13—C2132.09 (17)
C5—C4—H4121.0C13—C14—H14125.1
C4—C5—N3118.04 (18)C13—C14—C15109.80 (19)
C4—C5—C6123.28 (18)C15—C14—H14125.1
C6—C5—N3118.66 (19)C14—C15—H15122.8
C5—C6—H6120.4C16—C15—C14114.3 (2)
C7—C6—C5119.27 (19)C16—C15—H15122.8
C7—C6—H6120.4S2—C16—H16123.7
C6—C7—H7120.1C15—C16—S2112.70 (18)
C6—C7—C8119.78 (19)C15—C16—H16123.7
C8—C7—H7120.1
 

Funding information

This research was funded by a CCSU–AAUP research grant.

References

First citationBourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59–75.  Web of Science CrossRef IUCr Journals Google Scholar
First citationCrundwell, G., Sullivan, J., Pelto, R. & Kantardjieff, K. (2003). J. Chem. Cryst, 33, 239–244.  Web of Science CSD CrossRef CAS Google Scholar
First citationCrundwell, G., Meskill, T., Sayers, D. & Kantardjieff, K. (2002). Acta Cryst. E58, o666–o667.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationDu, M. & Zhao, X.-J. (2003). Acta Cryst. C59, o403–o405.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationFreitas, J. F. de, Brown, S., Oberndorfer, J. S. & Crundwell, G. (2020). IUCrData, 5, x200196.  Google Scholar
First citationOxford Diffraction (2009). CrysAlis CCD, CrysAlis RED and CrysAlis PRO. Oxford Diffraction, Yarnton, England.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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