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

Srinivasan, T.; Kalpana, V.; Rajakumar, P.; Velmurugan, D.

doi:10.1107/S1600536813007824

organic compounds

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ISSN: 2056-9890

Volume 69| Part 4| April 2013| Page o611

doi:10.1107/S1600536813007824

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

Thothadri Srinivasan,^a Venkatesan Kalpana,^b Perumal Rajakumar ^b and Devadasan Velmurugan ^a ^*

^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 ); Dubinina et al. (2006 ); Ellsworth et al. (2007 ); Mukaiyama et al. (2007 ). For a related structure, see: Nasir et al. (2010 ).

Experimental

Crystal data

C₁₄H₈Cl₂N₄O₂
M_r = 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 ) T_min = 0.869, T_max = 0.909
12550 measured reflections
3461 independent reflections
2835 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.092
S = 1.04
3461 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; 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 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813007824/pv2624sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813007824/pv2624Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813007824/pv2624Isup3.cml

checkCIF report

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.

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

	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.
	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

C₁₄H₈Cl₂N₄O₂	F(000) = 680
M_r = 335.14	D_x = 1.617 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3461 reflections
a = 11.083 (2) Å	θ = 1.9–28.5°
b = 10.0452 (17) Å	µ = 0.48 mm⁻¹
c = 12.846 (2) Å	T = 293 K
β = 105.681 (6)°	Block, colourless
V = 1376.9 (4) Å³	0.30 × 0.25 × 0.20 mm
Z = 4

Data collection top

Bruker SMART APEXII area-detector diffractometer	3461 independent reflections
Radiation source: fine-focus sealed tube	2835 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
ω and ϕ scans	θ_max = 28.5°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −14→14
T_min = 0.869, T_max = 0.909	k = −13→12
12550 measured reflections	l = −17→17

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.092	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0434P)² + 0.4056P] where P = (F_o² + 2F_c²)/3
3461 reflections	(Δ/σ)_max = 0.001
199 parameters	Δρ_max = 0.32 e Å⁻³
0 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

C₁₄H₈Cl₂N₄O₂	V = 1376.9 (4) Å³
M_r = 335.14	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 11.083 (2) Å	µ = 0.48 mm⁻¹
b = 10.0452 (17) Å	T = 293 K
c = 12.846 (2) Å	0.30 × 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)
T_min = 0.869, T_max = 0.909	R_int = 0.023
12550 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	0 restraints
wR(F²) = 0.092	H-atom parameters constrained
S = 1.04	Δρ_max = 0.32 e Å⁻³
3461 reflections	Δρ_min = −0.26 e Å⁻³
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

	x	y	z	U_iso*/U_eq
C1	0.22254 (14)	1.32153 (13)	1.02506 (11)	0.0359 (3)
C2	0.01581 (16)	1.31228 (17)	1.00820 (14)	0.0480 (4)
H2	−0.0583	1.3530	1.0117	0.058*
C3	0.01374 (15)	1.18158 (17)	0.97786 (13)	0.0453 (4)
H3	−0.0615	1.1350	0.9632	0.054*
C4	0.22027 (13)	1.18857 (13)	0.99072 (11)	0.0352 (3)
C5	0.32330 (13)	1.00672 (13)	0.93800 (13)	0.0387 (3)
C6	0.30055 (14)	0.99296 (15)	0.82880 (14)	0.0431 (3)
H6	0.2838	1.0671	0.7838	0.052*
C7	0.30274 (15)	0.86655 (15)	0.78589 (14)	0.0436 (3)
H7	0.2868	0.8545	0.7116	0.052*
C8	0.32871 (13)	0.75997 (13)	0.85454 (13)	0.0386 (3)
C9	0.35300 (17)	0.77452 (16)	0.96402 (14)	0.0494 (4)
H9	0.3712	0.7007	1.0092	0.059*
C10	0.35021 (17)	0.90062 (16)	1.00675 (15)	0.0495 (4)
H10	0.3664	0.9128	1.0810	0.059*
C11	0.24232 (12)	0.55046 (13)	0.79327 (11)	0.0333 (3)
C12	0.26134 (13)	0.41769 (14)	0.76895 (11)	0.0348 (3)
C13	0.05687 (15)	0.37541 (16)	0.74872 (13)	0.0447 (4)
H13	−0.0108	0.3171	0.7325	0.054*
C14	0.03882 (14)	0.50456 (16)	0.77375 (13)	0.0437 (3)
H14	−0.0409	0.5318	0.7752	0.052*
O1	0.32804 (10)	1.13575 (10)	0.98142 (10)	0.0464 (3)
O2	0.34166 (10)	0.63330 (10)	0.81253 (10)	0.0475 (3)
Cl1	0.36216 (4)	1.40754 (4)	1.05877 (4)	0.05003 (12)
Cl2	0.40796 (4)	0.36482 (4)	0.76640 (4)	0.05393 (13)
N1	0.12198 (14)	1.38253 (13)	1.03283 (11)	0.0445 (3)
N2	0.11690 (12)	1.11893 (12)	0.96874 (11)	0.0418 (3)
N3	0.13237 (11)	0.59329 (12)	0.79629 (11)	0.0397 (3)
N4	0.17015 (13)	0.33116 (12)	0.74704 (11)	0.0430 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0523 (8)	0.0232 (6)	0.0317 (7)	0.0015 (6)	0.0104 (6)	−0.0007 (5)
C2	0.0536 (9)	0.0444 (9)	0.0482 (9)	0.0148 (7)	0.0173 (7)	−0.0002 (7)
C3	0.0455 (8)	0.0433 (9)	0.0490 (9)	0.0019 (7)	0.0158 (7)	−0.0011 (7)
C4	0.0440 (7)	0.0246 (6)	0.0371 (7)	0.0019 (5)	0.0111 (6)	−0.0030 (5)
C5	0.0363 (7)	0.0233 (6)	0.0580 (9)	−0.0015 (5)	0.0153 (6)	−0.0111 (6)
C6	0.0485 (8)	0.0272 (7)	0.0546 (9)	−0.0001 (6)	0.0155 (7)	−0.0004 (6)
C7	0.0495 (8)	0.0351 (8)	0.0481 (9)	−0.0036 (6)	0.0163 (7)	−0.0082 (7)
C8	0.0340 (6)	0.0234 (6)	0.0604 (9)	−0.0027 (5)	0.0163 (6)	−0.0116 (6)
C9	0.0643 (10)	0.0274 (7)	0.0568 (10)	0.0043 (7)	0.0171 (8)	0.0004 (7)
C10	0.0648 (10)	0.0356 (8)	0.0478 (9)	0.0022 (7)	0.0149 (8)	−0.0073 (7)
C11	0.0384 (7)	0.0253 (6)	0.0359 (7)	−0.0015 (5)	0.0096 (5)	−0.0044 (5)
C12	0.0435 (7)	0.0268 (7)	0.0332 (7)	0.0020 (5)	0.0088 (6)	−0.0041 (5)
C13	0.0495 (8)	0.0409 (8)	0.0424 (8)	−0.0151 (7)	0.0101 (7)	−0.0062 (6)
C14	0.0374 (7)	0.0441 (8)	0.0486 (9)	−0.0045 (6)	0.0099 (6)	−0.0037 (7)
O1	0.0423 (5)	0.0261 (5)	0.0716 (8)	−0.0031 (4)	0.0168 (5)	−0.0173 (5)
O2	0.0401 (5)	0.0271 (5)	0.0798 (8)	−0.0047 (4)	0.0238 (5)	−0.0206 (5)
Cl1	0.0611 (2)	0.02891 (19)	0.0576 (3)	−0.00820 (16)	0.01178 (19)	−0.00849 (16)
Cl2	0.0508 (2)	0.0412 (2)	0.0695 (3)	0.01017 (16)	0.01584 (19)	−0.01644 (19)
N1	0.0605 (8)	0.0315 (6)	0.0420 (7)	0.0106 (6)	0.0146 (6)	−0.0013 (5)
N2	0.0452 (7)	0.0310 (6)	0.0507 (8)	−0.0008 (5)	0.0154 (6)	−0.0063 (5)
N3	0.0380 (6)	0.0306 (6)	0.0504 (7)	0.0005 (5)	0.0116 (5)	−0.0049 (5)
N4	0.0569 (8)	0.0293 (6)	0.0413 (7)	−0.0071 (5)	0.0107 (6)	−0.0073 (5)

Geometric parameters (Å, º) top

C1—N1	1.2991 (19)	C7—H7	0.9300
C1—C4	1.4047 (19)	C8—C9	1.366 (2)
C1—Cl1	1.7224 (16)	C8—O2	1.4046 (16)
C2—N1	1.335 (2)	C9—C10	1.384 (2)
C2—C3	1.368 (2)	C9—H9	0.9300
C2—H2	0.9300	C10—H10	0.9300
C3—N2	1.3377 (19)	C11—N3	1.3028 (18)
C3—H3	0.9300	C11—O2	1.3486 (16)
C4—N2	1.3065 (19)	C11—C12	1.3987 (19)
C4—O1	1.3415 (17)	C12—N4	1.3048 (19)
C5—C10	1.365 (2)	C12—Cl2	1.7184 (15)
C5—C6	1.364 (2)	C13—N4	1.337 (2)
C5—O1	1.4063 (16)	C13—C14	1.364 (2)
C6—C7	1.387 (2)	C13—H13	0.9300
C6—H6	0.9300	C14—N3	1.3383 (19)
C7—C8	1.367 (2)	C14—H14	0.9300

N1—C1—C4	121.98 (14)	C8—C9—C10	119.13 (15)
N1—C1—Cl1	118.38 (11)	C8—C9—H9	120.4
C4—C1—Cl1	119.64 (11)	C10—C9—H9	120.4
N1—C2—C3	121.38 (15)	C5—C10—C9	118.84 (16)
N1—C2—H2	119.3	C5—C10—H10	120.6
C3—C2—H2	119.3	C9—C10—H10	120.6
N2—C3—C2	121.84 (15)	N3—C11—O2	120.97 (12)
N2—C3—H3	119.1	N3—C11—C12	121.34 (13)
C2—C3—H3	119.1	O2—C11—C12	117.68 (12)
N2—C4—O1	121.26 (12)	N4—C12—C11	121.92 (13)
N2—C4—C1	121.15 (13)	N4—C12—Cl2	118.13 (11)
O1—C4—C1	117.60 (13)	C11—C12—Cl2	119.96 (11)
C10—C5—C6	122.27 (13)	N4—C13—C14	121.20 (14)
C10—C5—O1	119.01 (15)	N4—C13—H13	119.4
C6—C5—O1	118.56 (14)	C14—C13—H13	119.4
C5—C6—C7	118.91 (15)	N3—C14—C13	121.99 (14)
C5—C6—H6	120.5	N3—C14—H14	119.0
C7—C6—H6	120.5	C13—C14—H14	119.0
C8—C7—C6	118.93 (15)	C4—O1—C5	117.46 (11)
C8—C7—H7	120.5	C11—O2—C8	117.80 (11)
C6—C7—H7	120.5	C1—N1—C2	116.88 (13)
C9—C8—C7	121.91 (13)	C4—N2—C3	116.72 (13)
C9—C8—O2	118.70 (14)	C11—N3—C14	116.74 (12)
C7—C8—O2	119.15 (14)	C12—N4—C13	116.80 (13)

N1—C2—C3—N2	−1.7 (3)	N2—C4—O1—C5	5.5 (2)
N1—C1—C4—N2	−2.5 (2)	C1—C4—O1—C5	−174.53 (13)
Cl1—C1—C4—N2	177.22 (12)	C10—C5—O1—C4	−95.31 (18)
N1—C1—C4—O1	177.57 (14)	C6—C5—O1—C4	89.25 (17)
Cl1—C1—C4—O1	−2.73 (19)	N3—C11—O2—C8	11.1 (2)
C10—C5—C6—C7	1.1 (2)	C12—C11—O2—C8	−169.49 (14)
O1—C5—C6—C7	176.40 (13)	C9—C8—O2—C11	86.67 (18)
C5—C6—C7—C8	−0.6 (2)	C7—C8—O2—C11	−98.82 (17)
C6—C7—C8—C9	−0.3 (2)	C4—C1—N1—C2	1.0 (2)
C6—C7—C8—O2	−174.58 (13)	Cl1—C1—N1—C2	−178.69 (12)
C7—C8—C9—C10	0.6 (2)	C3—C2—N1—C1	1.0 (2)
O2—C8—C9—C10	174.91 (14)	O1—C4—N2—C3	−178.35 (14)
C6—C5—C10—C9	−0.8 (2)	C1—C4—N2—C3	1.7 (2)
O1—C5—C10—C9	−176.08 (15)	C2—C3—N2—C4	0.3 (2)
C8—C9—C10—C5	0.0 (3)	O2—C11—N3—C14	178.56 (14)
N3—C11—C12—N4	0.8 (2)	C12—C11—N3—C14	−0.8 (2)
O2—C11—C12—N4	−178.58 (14)	C13—C14—N3—C11	0.0 (2)
N3—C11—C12—Cl2	−179.68 (11)	C11—C12—N4—C13	0.1 (2)
O2—C11—C12—Cl2	0.94 (19)	Cl2—C12—N4—C13	−179.44 (11)
N4—C13—C14—N3	0.9 (3)	C14—C13—N4—C12	−0.9 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C13—H13···N3ⁱ	0.93	2.60	3.480 (2)	159

Symmetry code: (i) −x, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	C₁₄H₈Cl₂N₄O₂
M_r	335.14
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	11.083 (2), 10.0452 (17), 12.846 (2)
β (°)	105.681 (6)
V (Å³)	1376.9 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.48
Crystal size (mm)	0.30 × 0.25 × 0.20

Data collection
Diffractometer	Bruker SMART APEXII area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.869, 0.909
No. of measured, independent and observed [I > 2σ(I)] reflections	12550, 3461, 2835
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.672

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.092, 1.04
No. of reflections	3461
No. of parameters	199
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
C13—H13···N3ⁱ	0.93	2.60	3.480 (2)	159

Symmetry code: (i) −x, y−1/2, −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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