3-(4-Meth­oxy­phen­yl)pyrido[2,3-b]pyrazine

Wang, C.; Yan, J.; Chi, H.-J.; Dong, Y.; Zhang, Z.

doi:10.1107/S1600536810037943

organic compounds

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ISSN: 2056-9890

Volume 66| Part 10| October 2010| Page o2650

doi:10.1107/S1600536810037943

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3-(4-Methoxyphenyl)pyrido[2,3-b]pyrazine

Cui-ping Wang,^a Jing-bo Yan,^a Hai-Jun Chi,^a Yan Dong ^a and Zhi-qiang Zhang ^a ^*

^aSchool of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, People's Republic of China
^*Correspondence e-mail: zhao_submit@yahoo.com.cn

(Received 13 September 2010; accepted 22 September 2010; online 30 September 2010)

In the title molecule, C₁₄H₁₁N₃O, the benzene ring is twisted by 14.0 (2)° from the plane through the fused ring system. In the crystal, π–π interactions [centroid–centroid distances = 3.609 (1), 3.639 (1) and 3.735 (1) Å] form stacks of molecules propagating along the b axis. The crystal packing is further stabilized by weak intermolecular C—H⋯O and C—H⋯N hydrogen bonds.

Related literature

For a related structure, see: Koch et al. (2009 ). For the pharmacological properties of quinoxaline compounds, see: Kleim et al. (1995 ); Abasolo et al. (1987 ); Rodrigo et al. (2002 ).

Experimental

Crystal data

C₁₄H₁₁N₃O
M_r = 237.26
Monoclinic, P 2₁ /c
a = 6.4486 (13) Å
b = 7.3265 (15) Å
c = 24.216 (6) Å
β = 99.31 (3)°
V = 1129.0 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 153 K
0.20 × 0.18 × 0.12 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ) T_min = 0.982, T_max = 0.989
9650 measured reflections
2677 independent reflections
2221 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.146
S = 1.09
2677 reflections
165 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯N3ⁱ	0.95	2.54	3.361 (2)	145
C3—H3⋯O1ⁱⁱ	0.95	2.44	3.123 (2)	129
Symmetry codes: (i) -x+1, -y+1, -z; (ii) $[x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810037943/cv2765sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810037943/cv2765Isup2.hkl

checkCIF report

Comment top

Functionalized quinoxalines represent an important class of nitrogen-containing heterocycle which display a broad spectrum of biological activity. Similar structure had been reported by Koch (Koch et al., 2009). Quinoxaline derivatives were found to exhibit antimicrobial (Kleim et al. 1995), antitumor (Abasolo et al.,1987), and antituberculous activity (Rodrigo et al., 2002). Here, we report the synthesis and crystal structure of the title compound, (I) (Fig. 1).

The molecular structure of title compound (I) is as shown in Fig.1. The dihedral angle between the pyrido[2,3-b]pyrazine ring and benzene ring is 14.0 (2)°. The O atom attached to the phenyl ring don't deviate the phenyl ring with an r.m.s deviation of 0.0047 (3) Å. As a result of π-π conjugation, the C_sp²-O bond [O1—C9 = 1.3656 (13) Å] is significantly shorter than the C_sp³-O bond [O1—C14 = 1.4266 (15) Å]. The crystal structure is stabilized by weak C—H···N and C—H···O intermolecular interactions and π-π interactions between the Cg1 (centroid of N1/C1—C5) and Cg2 (centroid of C1/C2/N3/C6/C7/N2). Selected geometric parameters are shown in Table 1.

Related literature top

For a related structure, see: Koch et al. (2009). For the pharmacological properties of quinoxaline compounds, see: Kleim et al. (1995); Abasolo et al. (1987); Rodrigo et al. (2002).

Experimental top

A suspension of 2-(4-methoxyphenyl)-2-oxoacetaldehyde (2.0 mmol) and pyridine-2,3-diamine (3.0 mmol) in ethanol (5 ml) was stirred at room temperature. The reaction progress was monitored via TLC. The resulting precipitate was filtered off, washed with cold ethanol, dried and purified to give the target product as light yellow solid in 93% yield. Crystals of (I) suitable for single-crystal X-ray analysis were grown by slow evaporation of a solution in chloroform-ethanol (1:1).

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. View of the molecule of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

3-(4-Methoxyphenyl)pyrido[2,3-b]pyrazine top

Crystal data top

C₁₄H₁₁N₃O	F(000) = 496
M_r = 237.26	D_x = 1.396 Mg m⁻³
Monoclinic, P2₁/c	Melting point: 428 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 6.4486 (13) Å	Cell parameters from 3162 reflections
b = 7.3265 (15) Å	θ = 2.6–27.9°
c = 24.216 (6) Å	µ = 0.09 mm⁻¹
β = 99.31 (3)°	T = 153 K
V = 1129.0 (4) Å³	Prism, colourless
Z = 4	0.20 × 0.18 × 0.12 mm

Data collection top

Rigaku Saturn CCD area-detector diffractometer	2677 independent reflections
Radiation source: rotating anode	2221 reflections with I > 2σ(I)
Multilayer monochromator	R_int = 0.034
Detector resolution: 7.31 pixels mm^-1	θ_max = 27.9°, θ_min = 1.7°
ϕ and ω scans	h = −8→8
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −9→9
T_min = 0.982, T_max = 0.989	l = −19→31
9650 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.049	H-atom parameters constrained
wR(F²) = 0.146	w = 1/[σ²(F_o²) + (0.0916P)² + 0.0926P] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max = 0.001
2677 reflections	Δρ_max = 0.39 e Å⁻³
165 parameters	Δρ_min = −0.27 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.194 (16)

Crystal data top

C₁₄H₁₁N₃O	V = 1129.0 (4) Å³
M_r = 237.26	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 6.4486 (13) Å	µ = 0.09 mm⁻¹
b = 7.3265 (15) Å	T = 153 K
c = 24.216 (6) Å	0.20 × 0.18 × 0.12 mm
β = 99.31 (3)°

Data collection top

Rigaku Saturn CCD area-detector diffractometer	2677 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	2221 reflections with I > 2σ(I)
T_min = 0.982, T_max = 0.989	R_int = 0.034
9650 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.146	H-atom parameters constrained
S = 1.09	Δρ_max = 0.39 e Å⁻³
2677 reflections	Δρ_min = −0.27 e Å⁻³
165 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
O1	0.71204 (14)	0.63090 (12)	0.31035 (3)	0.0269 (3)
N1	1.25315 (15)	0.85321 (13)	0.01789 (4)	0.0217 (3)
N2	1.03617 (15)	0.75236 (12)	0.07944 (4)	0.0194 (3)
N3	0.73020 (15)	0.63878 (13)	−0.01163 (4)	0.0212 (3)
C1	1.06896 (17)	0.77325 (15)	0.02545 (5)	0.0180 (3)
C2	0.91672 (17)	0.71404 (15)	−0.02001 (5)	0.0187 (3)
C3	0.95826 (18)	0.73760 (16)	−0.07480 (5)	0.0221 (3)
H3	0.8603	0.6979	−0.1061	0.027*
C4	1.14169 (19)	0.81838 (16)	−0.08199 (5)	0.0237 (3)
H4	1.1734	0.8377	−0.1185	0.028*
C5	1.28488 (19)	0.87344 (16)	−0.03427 (5)	0.0228 (3)
H5	1.4127	0.9288	−0.0402	0.027*
C6	0.70072 (18)	0.62433 (15)	0.04042 (5)	0.0211 (3)
H6	0.5715	0.5753	0.0477	0.025*
C7	0.85538 (17)	0.67952 (15)	0.08691 (5)	0.0181 (3)
C8	0.81251 (17)	0.65886 (15)	0.14497 (5)	0.0193 (3)
C9	0.93848 (19)	0.75321 (17)	0.18866 (5)	0.0245 (3)
H9	1.0513	0.8266	0.1806	0.029*
C10	0.90077 (19)	0.74085 (17)	0.24297 (5)	0.0253 (3)
H10	0.9865	0.8063	0.2719	0.030*
C11	0.73669 (19)	0.63212 (15)	0.25539 (5)	0.0210 (3)
C12	0.61082 (19)	0.53616 (16)	0.21299 (5)	0.0235 (3)
H12	0.4993	0.4616	0.2213	0.028*
C13	0.65008 (18)	0.55069 (16)	0.15829 (5)	0.0227 (3)
H13	0.5640	0.4852	0.1294	0.027*
C14	0.5489 (2)	0.52103 (19)	0.32631 (5)	0.0320 (3)
H14A	0.4121	0.5671	0.3081	0.048*
H14B	0.5564	0.5260	0.3670	0.048*
H14C	0.5662	0.3945	0.3147	0.048*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0318 (5)	0.0324 (5)	0.0180 (5)	−0.0071 (4)	0.0082 (3)	−0.0017 (3)
N1	0.0205 (5)	0.0225 (5)	0.0226 (5)	−0.0010 (4)	0.0050 (4)	−0.0004 (4)
N2	0.0200 (5)	0.0199 (5)	0.0185 (5)	−0.0010 (4)	0.0034 (4)	−0.0008 (4)
N3	0.0191 (5)	0.0233 (5)	0.0204 (5)	−0.0008 (4)	0.0013 (4)	0.0005 (4)
C1	0.0182 (5)	0.0172 (5)	0.0186 (6)	0.0012 (4)	0.0024 (4)	−0.0007 (4)
C2	0.0189 (5)	0.0167 (5)	0.0203 (6)	0.0017 (4)	0.0026 (4)	0.0005 (4)
C3	0.0245 (6)	0.0225 (6)	0.0185 (6)	0.0018 (4)	0.0008 (4)	0.0003 (4)
C4	0.0280 (6)	0.0241 (6)	0.0201 (6)	0.0021 (5)	0.0069 (4)	0.0019 (5)
C5	0.0218 (6)	0.0223 (6)	0.0253 (6)	−0.0002 (4)	0.0069 (4)	0.0002 (4)
C6	0.0183 (5)	0.0229 (6)	0.0220 (6)	−0.0020 (4)	0.0029 (4)	0.0001 (4)
C7	0.0185 (5)	0.0164 (5)	0.0194 (6)	0.0005 (4)	0.0032 (4)	−0.0010 (4)
C8	0.0203 (5)	0.0194 (5)	0.0183 (6)	−0.0003 (4)	0.0032 (4)	−0.0011 (4)
C9	0.0241 (6)	0.0278 (6)	0.0218 (6)	−0.0078 (5)	0.0046 (4)	−0.0012 (4)
C10	0.0277 (6)	0.0283 (7)	0.0192 (6)	−0.0066 (5)	0.0015 (5)	−0.0032 (5)
C11	0.0244 (6)	0.0216 (6)	0.0178 (6)	0.0007 (4)	0.0058 (4)	0.0000 (4)
C12	0.0242 (6)	0.0230 (6)	0.0247 (6)	−0.0053 (4)	0.0080 (5)	−0.0017 (5)
C13	0.0247 (6)	0.0229 (6)	0.0209 (6)	−0.0045 (4)	0.0048 (4)	−0.0041 (4)
C14	0.0340 (7)	0.0412 (8)	0.0241 (6)	−0.0085 (6)	0.0141 (5)	−0.0009 (5)

Geometric parameters (Å, º) top

O1—C11	1.3656 (13)	C6—H6	0.9500
O1—C14	1.4266 (15)	C7—C8	1.4838 (15)
N1—C5	1.3203 (15)	C8—C13	1.3924 (16)
N1—C1	1.3630 (14)	C8—C9	1.4069 (16)
N2—C7	1.3210 (14)	C9—C10	1.3786 (16)
N2—C1	1.3662 (14)	C9—H9	0.9500
N3—C6	1.3089 (15)	C10—C11	1.3955 (16)
N3—C2	1.3678 (15)	C10—H10	0.9500
C1—C2	1.4192 (16)	C11—C12	1.3921 (17)
C2—C3	1.4061 (15)	C12—C13	1.3922 (16)
C3—C4	1.3588 (17)	C12—H12	0.9500
C3—H3	0.9500	C13—H13	0.9500
C4—C5	1.4161 (17)	C14—H14A	0.9800
C4—H4	0.9500	C14—H14B	0.9800
C5—H5	0.9500	C14—H14C	0.9800
C6—C7	1.4361 (16)

Cg1···Cg2ⁱ	3.639 (1)	Cg2···Cg2ⁱⁱ	3.735 (1)
Cg1···Cg2ⁱⁱ	3.609 (1)

C11—O1—C14	118.35 (9)	C13—C8—C9	118.02 (11)
C5—N1—C1	116.75 (10)	C13—C8—C7	122.69 (10)
C7—N2—C1	116.94 (10)	C9—C8—C7	119.28 (10)
C6—N3—C2	116.34 (9)	C10—C9—C8	121.05 (11)
N1—C1—N2	116.73 (10)	C10—C9—H9	119.5
N1—C1—C2	122.39 (11)	C8—C9—H9	119.5
N2—C1—C2	120.88 (10)	C9—C10—C11	120.00 (11)
N3—C2—C3	119.72 (10)	C9—C10—H10	120.0
N3—C2—C1	121.51 (11)	C11—C10—H10	120.0
C3—C2—C1	118.75 (11)	O1—C11—C12	124.73 (11)
C4—C3—C2	118.49 (11)	O1—C11—C10	115.19 (10)
C4—C3—H3	120.8	C12—C11—C10	120.08 (11)
C2—C3—H3	120.8	C11—C12—C13	119.28 (11)
C3—C4—C5	119.06 (11)	C11—C12—H12	120.4
C3—C4—H4	120.5	C13—C12—H12	120.4
C5—C4—H4	120.5	C12—C13—C8	121.56 (11)
N1—C5—C4	124.56 (11)	C12—C13—H13	119.2
N1—C5—H5	117.7	C8—C13—H13	119.2
C4—C5—H5	117.7	O1—C14—H14A	109.5
N3—C6—C7	122.78 (11)	O1—C14—H14B	109.5
N3—C6—H6	118.6	H14A—C14—H14B	109.5
C7—C6—H6	118.6	O1—C14—H14C	109.5
N2—C7—C6	121.51 (11)	H14A—C14—H14C	109.5
N2—C7—C8	118.35 (10)	H14B—C14—H14C	109.5
C6—C7—C8	120.13 (10)

C5—N1—C1—N2	−179.99 (9)	N3—C6—C7—N2	1.49 (17)
C5—N1—C1—C2	−0.10 (17)	N3—C6—C7—C8	−179.77 (10)
C7—N2—C1—N1	178.19 (9)	N2—C7—C8—C13	−166.08 (10)
C7—N2—C1—C2	−1.70 (16)	C6—C7—C8—C13	15.13 (16)
C6—N3—C2—C3	−178.71 (10)	N2—C7—C8—C9	14.63 (16)
C6—N3—C2—C1	−0.13 (17)	C6—C7—C8—C9	−164.15 (11)
N1—C1—C2—N3	−178.12 (9)	C13—C8—C9—C10	−0.79 (17)
N2—C1—C2—N3	1.77 (17)	C7—C8—C9—C10	178.54 (10)
N1—C1—C2—C3	0.47 (17)	C8—C9—C10—C11	0.59 (18)
N2—C1—C2—C3	−179.64 (9)	C14—O1—C11—C12	1.36 (17)
N3—C2—C3—C4	177.79 (10)	C14—O1—C11—C10	−179.27 (10)
C1—C2—C3—C4	−0.83 (17)	C9—C10—C11—O1	−179.45 (10)
C2—C3—C4—C5	0.83 (17)	C9—C10—C11—C12	−0.05 (18)
C1—N1—C5—C4	0.10 (17)	O1—C11—C12—C13	179.06 (10)
C3—C4—C5—N1	−0.48 (18)	C10—C11—C12—C13	−0.28 (17)
C2—N3—C6—C7	−1.43 (16)	C11—C12—C13—C8	0.06 (17)
C1—N2—C7—C6	0.18 (16)	C9—C8—C13—C12	0.46 (17)
C1—N2—C7—C8	−178.59 (9)	C7—C8—C13—C12	−178.84 (10)

Symmetry codes: (i) −x+2, −y+2, −z; (ii) −x+2, −y+1, −z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···N3ⁱⁱⁱ	0.95	2.54	3.361 (2)	145
C3—H3···O1^iv	0.95	2.44	3.123 (2)	129

Symmetry codes: (iii) −x+1, −y+1, −z; (iv) x, −y+3/2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₁N₃O
M_r	237.26
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	153
a, b, c (Å)	6.4486 (13), 7.3265 (15), 24.216 (6)
β (°)	99.31 (3)
V (Å³)	1129.0 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.20 × 0.18 × 0.12

Data collection
Diffractometer	Rigaku Saturn CCD area-detector diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku/MSC, 2005)
T_min, T_max	0.982, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	9650, 2677, 2221
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.657

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.146, 1.09
No. of reflections	2677
No. of parameters	165
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.27

Computer programs: CrystalClear (Rigaku/MSC, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···N3ⁱ	0.95	2.54	3.361 (2)	145.0
C3—H3···O1ⁱⁱ	0.95	2.44	3.123 (2)	129.0

Symmetry codes: (i) −x+1, −y+1, −z; (ii) x, −y+3/2, z−1/2.

Acknowledgements

The author is indebted to Beijing Amber Tech Co. Ltd for the offer of some reagents.

References

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