2,3-Bis(4-bromo­phen­yl)quinoxaline

Jian, F.-F.; Wang, K.-F.; Zhuang, R.-R.; Xiao, H.-L.

doi:10.1107/S160053680705516X

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 64| Part 1| January 2008| Page o76

https://doi.org/10.1107/S160053680705516X

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2,3-Bis(4-bromophenyl)quinoxaline

Fang-Fang Jian,^a ^* Ke-Fei Wang,^a Rui-Rui Zhuang ^a and Hai-Lian Xiao ^a

^aNew Materials and Function Coordination Chemistry Laboratory, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
^*Correspondence e-mail: ffj2003@163169.net

(Received 23 October 2007; accepted 1 November 2007; online 6 December 2007)

The title compound, C₂₀H₁₂Br₂N₂, was prepared by the reaction of 1-(3-bromophenyl)-2-(4-bromophenyl)ethane-1,2-dione with o-phenylenediamine in refluxing ethanol. In the molecule, all bond lengths and angles are within normal ranges. The dihedral angle between the two benzene rings is 34.89 (1)°. The dihedral angles between the benzene rings and the quinoxaline system are 57.23 (1) and 36.75 (1)°. The crystal packing is stabilized by van der Waals forces.

Related literature

For related literature, see: Brock et al. (1999 ); Dailey et al. (2001 ); Guillon et al. (1998 ); Kim et al. (1993 ); Patel et al. (2000 ); Rong et al. (2006 ).

Experimental

Crystal data

C₂₀H₁₂Br₂N₂
M_r = 440.14
Triclinic, $[P \overline 1]$
a = 6.0830 (12) Å
b = 12.018 (2) Å
c = 12.323 (3) Å
α = 105.47 (3)°
β = 91.89 (3)°
γ = 97.47 (3)°
V = 858.7 (3) Å³
Z = 2
Mo Kα radiation
μ = 4.72 mm⁻¹
T = 293 (2) K
0.20 × 0.18 × 0.15 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.404, T_max = 0.492
3338 measured reflections
2888 independent reflections
1824 reflections with I > 2σ(I)
R_int = 0.027
3 standard reflections every 100 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.128
S = 1.06
2888 reflections
217 parameters
H-atom parameters constrained
Δρ_max = 0.56 e Å⁻³
Δρ_min = −0.74 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: NRCVAX (Gabe et al., 1989 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1990 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053680705516X/hg2324sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680705516X/hg2324Isup2.hkl

checkCIF report

Comment top

Quinoxaline derivatives are an important class of nitrogen containing heterocycles and constitute useful intermediates in organic synthesis which have been reported for their applications in the fields of dyes (Brock et al., 1999) and have also been used as building blocks for the synthesis of organic semiconductors (Dailey et al., 2001). Tetrahydroquinoxaline derivatives are important from a therapeutic point of view since promising anti HIV agents (Patel et al., 2000), glucogen receptor antagonists (Guillon et al., 1998) and angiotens in receptor antagonists (Kim et al., 1993) possess this ring system. The title compound (I) was synthesized as part of our study of these ligands. Here we report the crystal structure of (I).

The structure of (I) is represented in Fig. 1. The bond lengths and angles are usual for this type of compound (Rong et al., 2006). The mean planes p1(C1 - C6) and p2 (N1,N2,C7 - C14) make a dihedral angle of 57.23 (1)°. The dihedral angles formed by phenyl ring(C8 –C13) and phenyl ring (C15 - C20) with p1 are 55.48 (1) and 64.80 (1)°, respectively. The dihedral angles between the benzene rings is 34.89 (1)°. The crystal packing (Fig. 2) is stabilized by van der Waals forces.

Related literature top

For related literature, see: Brock et al. (1999); Dailey et al. (2001); Guillon et al. (1998); Kim et al. (1993); Patel et al. (2000); Rong et al. (2006).

Experimental top

A mixture of 1-(3-bromophenyl)-2-(4-bromophenyl)ethane-1,2-dione (5.77 g, 0.02 mol) and o-phenylene diamine (2.16 g, 0.02 mol) was stirred in refluxing ethanol (30 ml) for 5 h to afford the title compound (3.25 g, yield 74%). Single crystals suitable for X-ray measurements were obtained by recrystallization from THF at room temperature.

Structure description top

For related literature, see: Brock et al. (1999); Dailey et al. (2001); Guillon et al. (1998); Kim et al. (1993); Patel et al. (2000); Rong et al. (2006).

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: NRCVAX (Gabe et al., 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1990); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure and atom-labeling scheme for (I), with displacement ellipsoids drawn at the 30% probability level.
	Fig. 2. The crystal packing of (I), viewed down the a axis.

2,3-Bis(4-bromophenyl)quinoxaline top

Crystal data top

C₂₀H₁₂Br₂N₂	Z = 2
M_r = 440.14	F(000) = 432
Triclinic, P1	D_x = 1.702 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.0830 (12) Å	Cell parameters from 25 reflections
b = 12.018 (2) Å	θ = 4–14°
c = 12.323 (3) Å	µ = 4.72 mm⁻¹
α = 105.47 (3)°	T = 293 K
β = 91.89 (3)°	Block, yellow
γ = 97.47 (3)°	0.20 × 0.18 × 0.15 mm
V = 858.7 (3) Å³

Data collection top

Enraf–Nonius CAD-4 diffractometer	1824 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.027
Graphite monochromator	θ_max = 25.0°, θ_min = 1.7°
ω scans	h = 0→7
Absorption correction: ψ scan (North et al., 1968)	k = −14→14
T_min = 0.404, T_max = 0.492	l = −14→14
3338 measured reflections	3 standard reflections every 100 reflections
2888 independent reflections	intensity decay: none

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.128	H-atom parameters constrained
S = 1.06	w = 1/[σ²(F_o²) + (0.0589P)² + 0.7939P] where P = (F_o² + 2F_c²)/3
2888 reflections	(Δ/σ)_max < 0.001
217 parameters	Δρ_max = 0.56 e Å⁻³
0 restraints	Δρ_min = −0.74 e Å⁻³

Crystal data top

C₂₀H₁₂Br₂N₂	γ = 97.47 (3)°
M_r = 440.14	V = 858.7 (3) Å³
Triclinic, P1	Z = 2
a = 6.0830 (12) Å	Mo Kα radiation
b = 12.018 (2) Å	µ = 4.72 mm⁻¹
c = 12.323 (3) Å	T = 293 K
α = 105.47 (3)°	0.20 × 0.18 × 0.15 mm
β = 91.89 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1824 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.027
T_min = 0.404, T_max = 0.492	3 standard reflections every 100 reflections
3338 measured reflections	intensity decay: none
2888 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	0 restraints
wR(F²) = 0.128	H-atom parameters constrained
S = 1.06	Δρ_max = 0.56 e Å⁻³
2888 reflections	Δρ_min = −0.74 e Å⁻³
217 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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
Br1	0.47031 (12)	0.83130 (5)	0.45247 (6)	0.0741 (3)
Br2	−0.24223 (11)	0.30938 (6)	−0.14438 (6)	0.0753 (3)
N1	0.7857 (7)	0.2921 (4)	0.3229 (4)	0.0493 (11)
N2	0.4951 (8)	0.1176 (4)	0.1656 (4)	0.0542 (12)
C1	0.3718 (9)	0.4705 (5)	0.3533 (5)	0.0526 (14)
H1B	0.2564	0.4116	0.3532	0.063*
C2	0.3425 (9)	0.5854 (5)	0.3977 (5)	0.0529 (14)
H2B	0.2112	0.6041	0.4297	0.064*
C3	0.5130 (10)	0.6720 (5)	0.3936 (5)	0.0522 (14)
C4	0.7127 (10)	0.6469 (5)	0.3496 (5)	0.0589 (15)
H4A	0.8255	0.7065	0.3480	0.071*
C5	0.7412 (9)	0.5309 (5)	0.3078 (5)	0.0544 (14)
H5A	0.8755	0.5129	0.2789	0.065*
C6	0.5720 (9)	0.4407 (4)	0.3082 (4)	0.0461 (13)
C7	0.6106 (9)	0.3173 (4)	0.2700 (4)	0.0462 (13)
C8	0.8169 (9)	0.1783 (5)	0.2990 (5)	0.0493 (13)
C9	0.9999 (10)	0.1469 (6)	0.3534 (5)	0.0652 (17)
H9A	1.1007	0.2046	0.4025	0.078*
C10	1.0281 (12)	0.0335 (6)	0.3342 (6)	0.0709 (18)
H10A	1.1480	0.0130	0.3695	0.085*
C11	0.8729 (12)	−0.0534 (6)	0.2597 (6)	0.0735 (19)
H11A	0.8904	−0.1314	0.2479	0.088*
C12	0.7000 (11)	−0.0263 (5)	0.2052 (6)	0.0694 (18)
H12A	0.6031	−0.0852	0.1551	0.083*
C13	0.6657 (9)	0.0901 (5)	0.2238 (5)	0.0505 (13)
C14	0.4677 (8)	0.2285 (4)	0.1856 (5)	0.0472 (13)
C15	0.2918 (9)	0.2540 (5)	0.1121 (4)	0.0477 (13)
C16	0.3189 (10)	0.3520 (5)	0.0707 (5)	0.0584 (15)
H16A	0.4455	0.4071	0.0940	0.070*
C17	0.1619 (10)	0.3685 (5)	−0.0041 (5)	0.0611 (16)
H17A	0.1836	0.4330	−0.0326	0.073*
C18	−0.0301 (9)	0.2875 (5)	−0.0366 (5)	0.0545 (14)
C19	−0.0638 (10)	0.1897 (5)	0.0024 (5)	0.0576 (15)
H19A	−0.1927	0.1362	−0.0200	0.069*
C20	0.0981 (9)	0.1728 (5)	0.0755 (5)	0.0516 (14)
H20A	0.0783	0.1062	0.1010	0.062*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0889 (5)	0.0564 (4)	0.0746 (5)	0.0182 (3)	0.0012 (4)	0.0107 (3)
Br2	0.0645 (4)	0.0854 (5)	0.0725 (5)	0.0068 (3)	−0.0241 (3)	0.0212 (4)
N1	0.044 (3)	0.053 (3)	0.049 (3)	0.009 (2)	−0.002 (2)	0.009 (2)
N2	0.048 (3)	0.056 (3)	0.057 (3)	−0.001 (2)	0.002 (2)	0.016 (2)
C1	0.040 (3)	0.056 (3)	0.057 (4)	0.001 (3)	−0.004 (3)	0.011 (3)
C2	0.039 (3)	0.065 (4)	0.052 (3)	0.011 (3)	−0.002 (3)	0.010 (3)
C3	0.059 (4)	0.051 (3)	0.045 (3)	0.010 (3)	−0.006 (3)	0.012 (3)
C4	0.050 (4)	0.056 (3)	0.066 (4)	−0.004 (3)	−0.001 (3)	0.014 (3)
C5	0.039 (3)	0.061 (3)	0.061 (4)	0.007 (3)	0.002 (3)	0.013 (3)
C6	0.041 (3)	0.053 (3)	0.041 (3)	0.004 (2)	−0.008 (2)	0.010 (2)
C7	0.041 (3)	0.053 (3)	0.044 (3)	0.004 (2)	0.001 (2)	0.013 (2)
C8	0.044 (3)	0.058 (3)	0.047 (3)	0.009 (3)	0.007 (3)	0.014 (3)
C9	0.059 (4)	0.073 (4)	0.064 (4)	0.022 (3)	−0.010 (3)	0.016 (3)
C10	0.076 (5)	0.075 (4)	0.072 (4)	0.033 (4)	0.001 (4)	0.027 (4)
C11	0.084 (5)	0.059 (4)	0.087 (5)	0.027 (4)	0.018 (4)	0.027 (4)
C12	0.065 (4)	0.054 (3)	0.087 (5)	0.003 (3)	0.000 (4)	0.019 (3)
C13	0.047 (3)	0.052 (3)	0.054 (3)	0.007 (3)	0.010 (3)	0.017 (3)
C14	0.037 (3)	0.051 (3)	0.050 (3)	0.000 (2)	0.004 (2)	0.011 (3)
C15	0.042 (3)	0.058 (3)	0.041 (3)	0.005 (2)	0.001 (2)	0.011 (3)
C16	0.051 (4)	0.061 (4)	0.057 (4)	−0.008 (3)	−0.010 (3)	0.015 (3)
C17	0.063 (4)	0.059 (3)	0.061 (4)	−0.002 (3)	−0.009 (3)	0.021 (3)
C18	0.043 (3)	0.071 (4)	0.045 (3)	0.008 (3)	−0.011 (3)	0.011 (3)
C19	0.049 (3)	0.070 (4)	0.048 (3)	−0.002 (3)	−0.004 (3)	0.013 (3)
C20	0.047 (3)	0.057 (3)	0.049 (3)	0.002 (3)	−0.002 (3)	0.014 (3)

Geometric parameters (Å, º) top

Br1—C3	1.913 (5)	C9—C10	1.355 (8)
Br2—C18	1.913 (5)	C9—H9A	0.9300
N1—C7	1.339 (6)	C10—C11	1.414 (9)
N1—C8	1.360 (7)	C10—H10A	0.9300
N2—C14	1.322 (7)	C11—C12	1.350 (9)
N2—C13	1.367 (7)	C11—H11A	0.9300
C1—C2	1.380 (8)	C12—C13	1.400 (8)
C1—C6	1.404 (8)	C12—H12A	0.9300
C1—H1B	0.9300	C14—C15	1.493 (7)
C2—C3	1.383 (8)	C15—C16	1.397 (8)
C2—H2B	0.9300	C15—C20	1.405 (7)
C3—C4	1.383 (8)	C16—C17	1.374 (8)
C4—C5	1.388 (8)	C16—H16A	0.9300
C4—H4A	0.9300	C17—C18	1.392 (8)
C5—C6	1.395 (7)	C17—H17A	0.9300
C5—H5A	0.9300	C18—C19	1.378 (8)
C6—C7	1.484 (7)	C19—C20	1.384 (7)
C7—C14	1.443 (7)	C19—H19A	0.9300
C8—C13	1.412 (7)	C20—H20A	0.9300
C8—C9	1.424 (7)

C7—N1—C8	117.5 (4)	C11—C10—H10A	120.4
C14—N2—C13	118.5 (4)	C12—C11—C10	121.8 (6)
C2—C1—C6	121.4 (5)	C12—C11—H11A	119.1
C2—C1—H1B	119.3	C10—C11—H11A	119.1
C6—C1—H1B	119.3	C11—C12—C13	120.4 (6)
C1—C2—C3	118.5 (5)	C11—C12—H12A	119.8
C1—C2—H2B	120.8	C13—C12—H12A	119.8
C3—C2—H2B	120.8	N2—C13—C12	120.2 (5)
C2—C3—C4	122.1 (5)	N2—C13—C8	120.9 (5)
C2—C3—Br1	118.5 (4)	C12—C13—C8	118.8 (5)
C4—C3—Br1	119.3 (4)	N2—C14—C7	120.4 (5)
C3—C4—C5	118.6 (5)	N2—C14—C15	115.8 (4)
C3—C4—H4A	120.7	C7—C14—C15	123.7 (5)
C5—C4—H4A	120.7	C16—C15—C20	118.0 (5)
C4—C5—C6	121.2 (5)	C16—C15—C14	122.4 (5)
C4—C5—H5A	119.4	C20—C15—C14	119.4 (5)
C6—C5—H5A	119.4	C17—C16—C15	121.2 (5)
C5—C6—C1	118.1 (5)	C17—C16—H16A	119.4
C5—C6—C7	120.4 (5)	C15—C16—H16A	119.4
C1—C6—C7	121.3 (5)	C16—C17—C18	119.2 (5)
N1—C7—C14	121.5 (5)	C16—C17—H17A	120.4
N1—C7—C6	114.9 (4)	C18—C17—H17A	120.4
C14—C7—C6	123.5 (5)	C19—C18—C17	121.5 (5)
N1—C8—C13	120.9 (5)	C19—C18—Br2	119.8 (4)
N1—C8—C9	119.7 (5)	C17—C18—Br2	118.6 (5)
C13—C8—C9	119.4 (5)	C18—C19—C20	118.6 (5)
C10—C9—C8	120.4 (6)	C18—C19—H19A	120.7
C10—C9—H9A	119.8	C20—C19—H19A	120.7
C8—C9—H9A	119.8	C19—C20—C15	121.5 (5)
C9—C10—C11	119.1 (6)	C19—C20—H20A	119.3
C9—C10—H10A	120.4	C15—C20—H20A	119.3

C6—C1—C2—C3	2.2 (8)	C11—C12—C13—C8	1.0 (9)
C1—C2—C3—C4	−1.9 (8)	N1—C8—C13—N2	5.8 (8)
C1—C2—C3—Br1	178.8 (4)	C9—C8—C13—N2	−176.5 (5)
C2—C3—C4—C5	0.4 (9)	N1—C8—C13—C12	−177.5 (5)
Br1—C3—C4—C5	179.7 (4)	C9—C8—C13—C12	0.2 (8)
C3—C4—C5—C6	0.9 (9)	C13—N2—C14—C7	−2.2 (8)
C4—C5—C6—C1	−0.6 (8)	C13—N2—C14—C15	174.7 (5)
C4—C5—C6—C7	−176.0 (5)	N1—C7—C14—N2	6.1 (8)
C2—C1—C6—C5	−1.0 (8)	C6—C7—C14—N2	−171.5 (5)
C2—C1—C6—C7	174.4 (5)	N1—C7—C14—C15	−170.5 (5)
C8—N1—C7—C14	−3.8 (8)	C6—C7—C14—C15	11.9 (8)
C8—N1—C7—C6	174.0 (5)	N2—C14—C15—C16	−140.4 (6)
C5—C6—C7—N1	54.7 (7)	C7—C14—C15—C16	36.3 (8)
C1—C6—C7—N1	−120.5 (6)	N2—C14—C15—C20	34.6 (7)
C5—C6—C7—C14	−127.6 (6)	C7—C14—C15—C20	−148.6 (6)
C1—C6—C7—C14	57.2 (7)	C20—C15—C16—C17	−0.3 (9)
C7—N1—C8—C13	−1.9 (8)	C14—C15—C16—C17	174.8 (5)
C7—N1—C8—C9	−179.6 (5)	C15—C16—C17—C18	1.7 (9)
N1—C8—C9—C10	177.2 (6)	C16—C17—C18—C19	−1.6 (9)
C13—C8—C9—C10	−0.5 (9)	C16—C17—C18—Br2	−178.0 (5)
C8—C9—C10—C11	−0.3 (10)	C17—C18—C19—C20	0.1 (9)
C9—C10—C11—C12	1.5 (11)	Br2—C18—C19—C20	176.5 (4)
C10—C11—C12—C13	−1.9 (11)	C18—C19—C20—C15	1.3 (9)
C14—N2—C13—C12	179.9 (6)	C16—C15—C20—C19	−1.2 (8)
C14—N2—C13—C8	−3.5 (8)	C14—C15—C20—C19	−176.5 (5)
C11—C12—C13—N2	177.7 (6)

Experimental details

Crystal data
Chemical formula	C₂₀H₁₂Br₂N₂
M_r	440.14
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	6.0830 (12), 12.018 (2), 12.323 (3)
α, β, γ (°)	105.47 (3), 91.89 (3), 97.47 (3)
V (Å³)	858.7 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	4.72
Crystal size (mm)	0.20 × 0.18 × 0.15

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.404, 0.492
No. of measured, independent and observed [I > 2σ(I)] reflections	3338, 2888, 1824
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.128, 1.06
No. of reflections	2888
No. of parameters	217
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.56, −0.74

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), NRCVAX (Gabe et al., 1989), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL/PC (Sheldrick, 1990), WinGX (Farrugia, 1999).

Acknowledgements

The authors thank the Natural Science Foundation of Shandong Province (grant No. Y2005B04).

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