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

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ISSN: 2056-9890

1,4-Bis(3-chloro­pyrazin-2-yl­­oxy)benzene

aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and bDepartment of Organic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, India
*Correspondence e-mail: shirai2011@gmail.com

(Received 3 March 2013; accepted 21 March 2013; online 28 March 2013)

In the title compound, C14H8Cl2N4O2, the pyrazine rings are orthogonal to the benzene ring, making dihedral angles of 88.42 (8) and 89.22 (8)°. The Cl atoms attached to the pyrazine rings deviate by −0.0597 (5) and 0.0009 (5) Å from the ring plane. The crystal structure features C—H⋯N hydrogen bonds.

Related literature

For applications of the pyrazine ring system in drug development, see: Du et al. (2009[Du, X. H., Gustin, D. J., Chen, X. Q., Duquette, J., McGee, L. R., Wang, Z. L., Ebsworth, K., Henne, K., Lemon, B., Ma, J., Miao, S. C., Sabalan, E., Sullivan, T. J., Tonn, G., Collins, T. L. & Medina, J. C. (2009). Bioorg. Med. Chem. Lett. 19, 5200-5204.]); Dubinina et al. (2006[Dubinina, G. G., Platonov, M. O., Golovach, S. M., Borysko, P. O., Tolmachov, A. O. & Volovenko, Y. M. (2006). Eur. J. Med. Chem. 41, 727-737.]); Ellsworth et al. (2007[Ellsworth, B. A., Wang, Y., Zhu, Y. H., Pendri, A., Gerritz, S. W., Sun, C. Q., Carlson, K. E., Kang, L. Y., Baska, R. A., Yang, Y. F., Huang, Q., Burford, N. T., Cullen, M. J., Johnghar, S., Behnia, K., Pelleymounter, M. A., Washburn, W. N. & Ewing, W. R. (2007). Bioorg. Med. Chem. Lett. 17, 3978-3982.]); Mukaiyama et al. (2007[Mukaiyama, H., Nishimura, T., Kobayashi, S., Ozawa, T., Kamada, N., Komatsu, Y., Kikuchi, S., Oonota, H. & Kusama, H. (2007). Bioorg. Med. Chem. Lett. 15, 868-885.]). For a related structure, see: Nasir et al. (2010[Nasir, S. B., Abdullah, Z., Fairuz, Z. A., Ng, S. W. & Tiekink, E. R. T. (2010). Acta Cryst. E66, o2187.]).

[Scheme 1]

Experimental

Crystal data
  • C14H8Cl2N4O2

  • Mr = 335.14

  • Monoclinic, P 21 /c

  • a = 11.083 (2) Å

  • b = 10.0452 (17) Å

  • c = 12.846 (2) Å

  • β = 105.681 (6)°

  • V = 1376.9 (4) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.48 mm−1

  • T = 293 K

  • 0.30 × 0.25 × 0.20 mm

Data collection
  • Bruker SMART APEXII area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.869, Tmax = 0.909

  • 12550 measured reflections

  • 3461 independent reflections

  • 2835 reflections with I > 2σ(I)

  • Rint = 0.023

Refinement
  • R[F2 > 2σ(F2)] = 0.032

  • wR(F2) = 0.092

  • S = 1.04

  • 3461 reflections

  • 199 parameters

  • H-atom parameters constrained

  • Δρmax = 0.32 e Å−3

  • Δρmin = −0.26 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C13—H13⋯N3i 0.93 2.60 3.480 (2) 159
Symmetry code: (i) [-x, y-{\script{1\over 2}}, -z+{\script{3\over 2}}].

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

The pyrazine ring is a useful structural unit in medicinal chemistry and has found broad applications in drug development and can be used as antiproliferative agent (Dubinina et al., 2006), potent CXCR3 antagonist (Du et al., 2009), CB1 antagonist (Ellsworth et al., 2007) and c-Src inhibitor (Mukaiyama et al., 2007). In view of different applications of this class of compounds, we have undertaken the single-crystal structure determination of the title compound.

The bond distances and angles in the title compound (Fig. 1) agree very well with the corresponding bond distances and angles reported in a closely related compound (Nasir et al., 2010). In the titled compound, the pyrazine ring (N1/N2/C1-C4) makes a dihedral angle of 88.42 (8)° with the benzene ring (C5-C10), which shows that these are orthogonal to each other. The other pyrazine ring (N3/N4/C11-C14) makes a dihedral angle of 89.22 (8)° with the bezene ring, which also shows that these are also orthogonal to each other. The dihedral angle between the two pyrazine rings is 3.18 (7)°. The chlorine atoms Cl1 and Cl2 attached with the pyrazine rings deviate by -0.0597 (5) and 0.0009 (5)Å. The crystal packing is stabilised by intermolecular C–H···N hydrogen bonds (Tab. 1 & Fig. 2).

Related literature top

For applications of the pyrazine ring system in drug development, see: Du et al. (2009); Dubinina et al. (2006); Ellsworth et al. (2007); Mukaiyama et al. (2007). For a related structure, see: Nasir et al. (2010).

Experimental top

To a stirred solution of Cs2CO3/K2CO3 (22 mmol) in CH3CN (50 mL), dihydroxybenzenes (10 mmol) was added and stirred for 5 min. 2,3-Dichloropyrazine (20 mmol) in CH3CN (100 mL) was added dropwise to the above reaction mixture and stirring was allowed at refluxing condition for 12 h. After the reaction was complete, the reaction mixture was allowed to attain room temperature and then evaporated to dryness. The residue obtained was extracted with CH2Cl2 (3 x 100 mL), washed with water (3 x 100 mL), brine and then dried over Na2SO4. Evaporation of the organic layer gave a residue, which on purification using column chromatography with hexane/CHCl3 (1:1) as an eluent gave the corresponding compound. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the title compound in hexane at room temperature.

Refinement top

The hydrogen atoms were placed in calculated positions with C—H = 0.93 Å, refined in the riding model with fixed isotropic displacement parameters: Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); 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); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids drawn at the 30% probability level. H atoms are presented as small spheres of arbitrary radius.
[Figure 2] Fig. 2. The crystal packing of the title compound viewed down c axis. H-atoms not involved in H-bonds have been excluded for clarity.
1,4-Bis(3-chloropyrazin-2-yloxy)benzene top
Crystal data top
C14H8Cl2N4O2F(000) = 680
Mr = 335.14Dx = 1.617 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3461 reflections
a = 11.083 (2) Åθ = 1.9–28.5°
b = 10.0452 (17) ŵ = 0.48 mm1
c = 12.846 (2) ÅT = 293 K
β = 105.681 (6)°Block, colourless
V = 1376.9 (4) Å30.30 × 0.25 × 0.20 mm
Z = 4
Data collection top
Bruker SMART APEXII area-detector
diffractometer
3461 independent reflections
Radiation source: fine-focus sealed tube2835 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
ω and ϕ scansθmax = 28.5°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 1414
Tmin = 0.869, Tmax = 0.909k = 1312
12550 measured reflectionsl = 1717
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)] = 0.032Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.092H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0434P)2 + 0.4056P]
where P = (Fo2 + 2Fc2)/3
3461 reflections(Δ/σ)max = 0.001
199 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = 0.26 e Å3
Crystal data top
C14H8Cl2N4O2V = 1376.9 (4) Å3
Mr = 335.14Z = 4
Monoclinic, P21/cMo Kα radiation
a = 11.083 (2) ŵ = 0.48 mm1
b = 10.0452 (17) ÅT = 293 K
c = 12.846 (2) Å0.30 × 0.25 × 0.20 mm
β = 105.681 (6)°
Data collection top
Bruker SMART APEXII area-detector
diffractometer
3461 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
2835 reflections with I > 2σ(I)
Tmin = 0.869, Tmax = 0.909Rint = 0.023
12550 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0320 restraints
wR(F2) = 0.092H-atom parameters constrained
S = 1.04Δρmax = 0.32 e Å3
3461 reflectionsΔρmin = 0.26 e Å3
199 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.22254 (14)1.32153 (13)1.02506 (11)0.0359 (3)
C20.01581 (16)1.31228 (17)1.00820 (14)0.0480 (4)
H20.05831.35301.01170.058*
C30.01374 (15)1.18158 (17)0.97786 (13)0.0453 (4)
H30.06151.13500.96320.054*
C40.22027 (13)1.18857 (13)0.99072 (11)0.0352 (3)
C50.32330 (13)1.00672 (13)0.93800 (13)0.0387 (3)
C60.30055 (14)0.99296 (15)0.82880 (14)0.0431 (3)
H60.28381.06710.78380.052*
C70.30274 (15)0.86655 (15)0.78589 (14)0.0436 (3)
H70.28680.85450.71160.052*
C80.32871 (13)0.75997 (13)0.85454 (13)0.0386 (3)
C90.35300 (17)0.77452 (16)0.96402 (14)0.0494 (4)
H90.37120.70071.00920.059*
C100.35021 (17)0.90062 (16)1.00675 (15)0.0495 (4)
H100.36640.91281.08100.059*
C110.24232 (12)0.55046 (13)0.79327 (11)0.0333 (3)
C120.26134 (13)0.41769 (14)0.76895 (11)0.0348 (3)
C130.05687 (15)0.37541 (16)0.74872 (13)0.0447 (4)
H130.01080.31710.73250.054*
C140.03882 (14)0.50456 (16)0.77375 (13)0.0437 (3)
H140.04090.53180.77520.052*
O10.32804 (10)1.13575 (10)0.98142 (10)0.0464 (3)
O20.34166 (10)0.63330 (10)0.81253 (10)0.0475 (3)
Cl10.36216 (4)1.40754 (4)1.05877 (4)0.05003 (12)
Cl20.40796 (4)0.36482 (4)0.76640 (4)0.05393 (13)
N10.12198 (14)1.38253 (13)1.03283 (11)0.0445 (3)
N20.11690 (12)1.11893 (12)0.96874 (11)0.0418 (3)
N30.13237 (11)0.59329 (12)0.79629 (11)0.0397 (3)
N40.17015 (13)0.33116 (12)0.74704 (11)0.0430 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0523 (8)0.0232 (6)0.0317 (7)0.0015 (6)0.0104 (6)0.0007 (5)
C20.0536 (9)0.0444 (9)0.0482 (9)0.0148 (7)0.0173 (7)0.0002 (7)
C30.0455 (8)0.0433 (9)0.0490 (9)0.0019 (7)0.0158 (7)0.0011 (7)
C40.0440 (7)0.0246 (6)0.0371 (7)0.0019 (5)0.0111 (6)0.0030 (5)
C50.0363 (7)0.0233 (6)0.0580 (9)0.0015 (5)0.0153 (6)0.0111 (6)
C60.0485 (8)0.0272 (7)0.0546 (9)0.0001 (6)0.0155 (7)0.0004 (6)
C70.0495 (8)0.0351 (8)0.0481 (9)0.0036 (6)0.0163 (7)0.0082 (7)
C80.0340 (6)0.0234 (6)0.0604 (9)0.0027 (5)0.0163 (6)0.0116 (6)
C90.0643 (10)0.0274 (7)0.0568 (10)0.0043 (7)0.0171 (8)0.0004 (7)
C100.0648 (10)0.0356 (8)0.0478 (9)0.0022 (7)0.0149 (8)0.0073 (7)
C110.0384 (7)0.0253 (6)0.0359 (7)0.0015 (5)0.0096 (5)0.0044 (5)
C120.0435 (7)0.0268 (7)0.0332 (7)0.0020 (5)0.0088 (6)0.0041 (5)
C130.0495 (8)0.0409 (8)0.0424 (8)0.0151 (7)0.0101 (7)0.0062 (6)
C140.0374 (7)0.0441 (8)0.0486 (9)0.0045 (6)0.0099 (6)0.0037 (7)
O10.0423 (5)0.0261 (5)0.0716 (8)0.0031 (4)0.0168 (5)0.0173 (5)
O20.0401 (5)0.0271 (5)0.0798 (8)0.0047 (4)0.0238 (5)0.0206 (5)
Cl10.0611 (2)0.02891 (19)0.0576 (3)0.00820 (16)0.01178 (19)0.00849 (16)
Cl20.0508 (2)0.0412 (2)0.0695 (3)0.01017 (16)0.01584 (19)0.01644 (19)
N10.0605 (8)0.0315 (6)0.0420 (7)0.0106 (6)0.0146 (6)0.0013 (5)
N20.0452 (7)0.0310 (6)0.0507 (8)0.0008 (5)0.0154 (6)0.0063 (5)
N30.0380 (6)0.0306 (6)0.0504 (7)0.0005 (5)0.0116 (5)0.0049 (5)
N40.0569 (8)0.0293 (6)0.0413 (7)0.0071 (5)0.0107 (6)0.0073 (5)
Geometric parameters (Å, º) top
C1—N11.2991 (19)C7—H70.9300
C1—C41.4047 (19)C8—C91.366 (2)
C1—Cl11.7224 (16)C8—O21.4046 (16)
C2—N11.335 (2)C9—C101.384 (2)
C2—C31.368 (2)C9—H90.9300
C2—H20.9300C10—H100.9300
C3—N21.3377 (19)C11—N31.3028 (18)
C3—H30.9300C11—O21.3486 (16)
C4—N21.3065 (19)C11—C121.3987 (19)
C4—O11.3415 (17)C12—N41.3048 (19)
C5—C101.365 (2)C12—Cl21.7184 (15)
C5—C61.364 (2)C13—N41.337 (2)
C5—O11.4063 (16)C13—C141.364 (2)
C6—C71.387 (2)C13—H130.9300
C6—H60.9300C14—N31.3383 (19)
C7—C81.367 (2)C14—H140.9300
N1—C1—C4121.98 (14)C8—C9—C10119.13 (15)
N1—C1—Cl1118.38 (11)C8—C9—H9120.4
C4—C1—Cl1119.64 (11)C10—C9—H9120.4
N1—C2—C3121.38 (15)C5—C10—C9118.84 (16)
N1—C2—H2119.3C5—C10—H10120.6
C3—C2—H2119.3C9—C10—H10120.6
N2—C3—C2121.84 (15)N3—C11—O2120.97 (12)
N2—C3—H3119.1N3—C11—C12121.34 (13)
C2—C3—H3119.1O2—C11—C12117.68 (12)
N2—C4—O1121.26 (12)N4—C12—C11121.92 (13)
N2—C4—C1121.15 (13)N4—C12—Cl2118.13 (11)
O1—C4—C1117.60 (13)C11—C12—Cl2119.96 (11)
C10—C5—C6122.27 (13)N4—C13—C14121.20 (14)
C10—C5—O1119.01 (15)N4—C13—H13119.4
C6—C5—O1118.56 (14)C14—C13—H13119.4
C5—C6—C7118.91 (15)N3—C14—C13121.99 (14)
C5—C6—H6120.5N3—C14—H14119.0
C7—C6—H6120.5C13—C14—H14119.0
C8—C7—C6118.93 (15)C4—O1—C5117.46 (11)
C8—C7—H7120.5C11—O2—C8117.80 (11)
C6—C7—H7120.5C1—N1—C2116.88 (13)
C9—C8—C7121.91 (13)C4—N2—C3116.72 (13)
C9—C8—O2118.70 (14)C11—N3—C14116.74 (12)
C7—C8—O2119.15 (14)C12—N4—C13116.80 (13)
N1—C2—C3—N21.7 (3)N2—C4—O1—C55.5 (2)
N1—C1—C4—N22.5 (2)C1—C4—O1—C5174.53 (13)
Cl1—C1—C4—N2177.22 (12)C10—C5—O1—C495.31 (18)
N1—C1—C4—O1177.57 (14)C6—C5—O1—C489.25 (17)
Cl1—C1—C4—O12.73 (19)N3—C11—O2—C811.1 (2)
C10—C5—C6—C71.1 (2)C12—C11—O2—C8169.49 (14)
O1—C5—C6—C7176.40 (13)C9—C8—O2—C1186.67 (18)
C5—C6—C7—C80.6 (2)C7—C8—O2—C1198.82 (17)
C6—C7—C8—C90.3 (2)C4—C1—N1—C21.0 (2)
C6—C7—C8—O2174.58 (13)Cl1—C1—N1—C2178.69 (12)
C7—C8—C9—C100.6 (2)C3—C2—N1—C11.0 (2)
O2—C8—C9—C10174.91 (14)O1—C4—N2—C3178.35 (14)
C6—C5—C10—C90.8 (2)C1—C4—N2—C31.7 (2)
O1—C5—C10—C9176.08 (15)C2—C3—N2—C40.3 (2)
C8—C9—C10—C50.0 (3)O2—C11—N3—C14178.56 (14)
N3—C11—C12—N40.8 (2)C12—C11—N3—C140.8 (2)
O2—C11—C12—N4178.58 (14)C13—C14—N3—C110.0 (2)
N3—C11—C12—Cl2179.68 (11)C11—C12—N4—C130.1 (2)
O2—C11—C12—Cl20.94 (19)Cl2—C12—N4—C13179.44 (11)
N4—C13—C14—N30.9 (3)C14—C13—N4—C120.9 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C13—H13···N3i0.932.603.480 (2)159
Symmetry code: (i) x, y1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC14H8Cl2N4O2
Mr335.14
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)11.083 (2), 10.0452 (17), 12.846 (2)
β (°) 105.681 (6)
V3)1376.9 (4)
Z4
Radiation typeMo Kα
µ (mm1)0.48
Crystal size (mm)0.30 × 0.25 × 0.20
Data collection
DiffractometerBruker SMART APEXII area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2008)
Tmin, Tmax0.869, 0.909
No. of measured, independent and
observed [I > 2σ(I)] reflections
12550, 3461, 2835
Rint0.023
(sin θ/λ)max1)0.672
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.032, 0.092, 1.04
No. of reflections3461
No. of parameters199
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.32, 0.26

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C13—H13···N3i0.932.603.480 (2)159
Symmetry code: (i) x, y1/2, z+3/2.
 

Acknowledgements

The authors thank the TBI X-ray facility and the UGC (SAP), CAS in Crystallography and Biophysics, University of Madras, India, for the data collection and other facilities. TS also thanks the DST for an Inspire fellowship.

References

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