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ISSN: 2056-9890

Methyl pyrazine-2-carboxyl­ate

aDepartment of Chemistry and Chemical Industry, Binzhou University, Binzhou, Shandong Province 256600, People's Republic of China, and bDepartment of Chemical Industry, Shandong Institute of Light Industry, Jinan 250353, People's Republic of China
*Correspondence e-mail: tanxuejie@163.com

(Received 7 October 2009; accepted 21 October 2009; online 28 October 2009)

The title compound, C6H6N2O2, is approximately planar [r.m.s. deviation = 0.0488 (3) Å]. In the crystal, weak inter­molecular C—H⋯O and C—H⋯N inter­actions join the mol­ecules into an infinite three-dimensional network.

Related literature

For the synthetic procedure, see: Kim et al. (2004[Kim, J. W., Choi, K. D., Lim, J. W., Lee, K. H. & Lee, S. H. (2004). PCT Int. Appl. WO 2004048369.]). For reduction of heteroaromatic esters, see: Boechat et al. (2005[Boechat, N., Costa, J. C. S., Mendonca, J. S., Paes, K. C., Fernandes, E. L., Oliveira, P. S. M., Vasconcelos, T. R. A. & Souza, M. V. N. (2005). Synth. Commun. 35, 3187-3190.]). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999[Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford University Press.]).

[Scheme 1]

Experimental

Crystal data
  • C6H6N2O2

  • Mr = 138.13

  • Orthorhombic, P 21 21 21

  • a = 3.865 (2) Å

  • b = 6.690 (4) Å

  • c = 24.92 (2) Å

  • V = 644.4 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 298 K

  • 0.32 × 0.12 × 0.05 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2000[Bruker (2000). SMART), SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.980, Tmax = 0.994

  • 3378 measured reflections

  • 757 independent reflections

  • 505 reflections with I > 2σ(I)

  • Rint = 0.080

Refinement
  • R[F2 > 2σ(F2)] = 0.066

  • wR(F2) = 0.153

  • S = 1.05

  • 757 reflections

  • 91 parameters

  • H-atom parameters constrained

  • Δρmax = 0.18 e Å−3

  • Δρmin = −0.17 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H2⋯O2i 0.93 2.35 3.205 (3) 153
C6—H4⋯N1ii 0.96 2.62 3.582 (3) 177
Symmetry codes: (i) x+1, y-1, z; (ii) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}].

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART), SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART), SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (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: SHELXTL; 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

Heteroaromatic esters are more easily reduced than the corresponding free acids (Boechat et al. 2005). The title compound, (I) (Fig. 1), [C6H6N2O2], was obtained as an intermediate in the synthesis of another pyrazine-based compound.

All non-hydrogen atoms of (I) are coplanar. The maximum deviation from the mean plane is 0.1249 (4) Å for O2 and the mean deviation is only 0.0488 (3) Å. The almost perfect planarity of the molecule reflects its efficient π-conjugation.

There are no classical hydrogen bonds present in the crystal structure (Spek, 2009). Nevertheless, there are weak C—H···O and C—H···N hydrogen bonds (Table 1, Desiraju & Steiner, 1999) linking the molecules into an infinite three-dimensional network [Fig. 2].

Related literature top

For the synthetic procedure, see: Kim et al. (2004). For reduction of heteroaromatic esters, see: Boechat et al. (2005). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999).

Experimental top

Compound (I) was prepared following a procedure published by Kim et al. (2004), but the product is not "pale brown" but colorless. Elemental analysis Calcd: C 52.17, H 4.38, N 20.28%. Found: C 51.87, H 4.02, N 20.14%.

Refinement top

Since the compound itself is achiral and in the absence of significant anomalous dispersion effects, Friedel pairs were averaged. All H atoms were fixed geometrically and allowed to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å, and with Uiso(H) = 1.2 Ueq(C) for CH groups of the pyrazine ring and Uiso(H) = 1.5 Ueq(C) for the methyl group.

Structure description top

Heteroaromatic esters are more easily reduced than the corresponding free acids (Boechat et al. 2005). The title compound, (I) (Fig. 1), [C6H6N2O2], was obtained as an intermediate in the synthesis of another pyrazine-based compound.

All non-hydrogen atoms of (I) are coplanar. The maximum deviation from the mean plane is 0.1249 (4) Å for O2 and the mean deviation is only 0.0488 (3) Å. The almost perfect planarity of the molecule reflects its efficient π-conjugation.

There are no classical hydrogen bonds present in the crystal structure (Spek, 2009). Nevertheless, there are weak C—H···O and C—H···N hydrogen bonds (Table 1, Desiraju & Steiner, 1999) linking the molecules into an infinite three-dimensional network [Fig. 2].

For the synthetic procedure, see: Kim et al. (2004). For reduction of heteroaromatic esters, see: Boechat et al. (2005). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The packing of (I), viewed down the a axis, showing one layer of molecules connected by C—H···O and C—H···N hydrogen bonds (dashed lines).
Methyl pyrazine-2-carboxylate top
Crystal data top
C6H6N2O2F(000) = 288
Mr = 138.13Dx = 1.424 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 378 reflections
a = 3.865 (2) Åθ = 1.6–25.5°
b = 6.690 (4) ŵ = 0.11 mm1
c = 24.92 (2) ÅT = 298 K
V = 644.4 (7) Å3Needle, colourless
Z = 40.32 × 0.12 × 0.05 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
757 independent reflections
Radiation source: fine-focus sealed tube505 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.080
π and ω scansθmax = 25.5°, θmin = 1.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
h = 44
Tmin = 0.980, Tmax = 0.994k = 78
3378 measured reflectionsl = 3022
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)] = 0.066Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.153H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0698P)2]
where P = (Fo2 + 2Fc2)/3
757 reflections(Δ/σ)max = 0.001
91 parametersΔρmax = 0.18 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C6H6N2O2V = 644.4 (7) Å3
Mr = 138.13Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 3.865 (2) ŵ = 0.11 mm1
b = 6.690 (4) ÅT = 298 K
c = 24.92 (2) Å0.32 × 0.12 × 0.05 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
757 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
505 reflections with I > 2σ(I)
Tmin = 0.980, Tmax = 0.994Rint = 0.080
3378 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0660 restraints
wR(F2) = 0.153H-atom parameters constrained
S = 1.05Δρmax = 0.18 e Å3
757 reflectionsΔρmin = 0.17 e Å3
91 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
xyzUiso*/Ueq
C10.2013 (5)0.6623 (3)0.93604 (7)0.0546 (6)
H10.09590.77140.95240.065*
C20.2602 (4)0.6690 (2)0.88246 (6)0.0371 (5)
C30.5035 (6)0.3674 (2)0.88599 (7)0.0561 (6)
H20.61330.25940.86980.067*
C40.4367 (6)0.3607 (3)0.93986 (7)0.0604 (6)
H30.49990.24700.95890.072*
C50.1459 (4)0.8493 (2)0.85163 (6)0.0395 (5)
C60.1405 (5)1.0165 (2)0.76991 (8)0.0642 (7)
H40.25691.01390.73590.096*
H50.19551.13850.78830.096*
H60.10491.00890.76430.096*
N10.4157 (4)0.52391 (19)0.85628 (6)0.0479 (5)
N20.2869 (5)0.5082 (2)0.96584 (6)0.0665 (6)
O10.2516 (3)0.84861 (17)0.80180 (4)0.0514 (4)
O20.0298 (4)0.97530 (17)0.87108 (5)0.0690 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0681 (13)0.0448 (11)0.0508 (10)0.0017 (11)0.0019 (11)0.0020 (10)
C20.0335 (8)0.0284 (8)0.0494 (10)0.0006 (8)0.0029 (9)0.0011 (8)
C30.0621 (12)0.0330 (9)0.0733 (12)0.0112 (11)0.0098 (11)0.0040 (10)
C40.0677 (13)0.0406 (10)0.0728 (12)0.0014 (11)0.0187 (12)0.0199 (10)
C50.0409 (10)0.0302 (8)0.0475 (10)0.0001 (9)0.0019 (9)0.0023 (9)
C60.0719 (15)0.0541 (11)0.0666 (13)0.0086 (12)0.0045 (11)0.0180 (11)
N10.0535 (9)0.0344 (7)0.0559 (9)0.0089 (8)0.0002 (8)0.0017 (8)
N20.0891 (12)0.0549 (10)0.0554 (10)0.0024 (11)0.0065 (10)0.0083 (9)
O10.0664 (8)0.0412 (6)0.0465 (7)0.0105 (7)0.0004 (7)0.0083 (6)
O20.0935 (10)0.0428 (7)0.0705 (9)0.0264 (8)0.0187 (8)0.0033 (7)
Geometric parameters (Å, º) top
C1—N21.312 (2)C4—N21.315 (3)
C1—C21.355 (2)C4—H30.9300
C1—H10.9300C5—O21.186 (2)
C2—N11.315 (2)C5—O11.307 (2)
C2—C51.497 (2)C6—O11.441 (2)
C3—N11.327 (2)C6—H40.9600
C3—C41.368 (3)C6—H50.9600
C3—H20.9300C6—H60.9600
N2—C1—C2122.76 (17)O2—C5—O1124.72 (15)
N2—C1—H1118.6O2—C5—C2122.14 (15)
C2—C1—H1118.6O1—C5—C2113.11 (14)
N1—C2—C1122.77 (15)O1—C6—H4109.5
N1—C2—C5118.36 (15)O1—C6—H5109.5
C1—C2—C5118.87 (15)H4—C6—H5109.5
N1—C3—C4121.68 (17)O1—C6—H6109.5
N1—C3—H2119.2H4—C6—H6109.5
C4—C3—H2119.2H5—C6—H6109.5
N2—C4—C3122.83 (17)C2—N1—C3114.99 (15)
N2—C4—H3118.6C1—N2—C4114.94 (16)
C3—C4—H3118.6C5—O1—C6115.33 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O2i0.932.353.205 (3)153
C6—H4···N1ii0.962.623.582 (3)177
Symmetry codes: (i) x+1, y1, z; (ii) x+1, y+1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC6H6N2O2
Mr138.13
Crystal system, space groupOrthorhombic, P212121
Temperature (K)298
a, b, c (Å)3.865 (2), 6.690 (4), 24.92 (2)
V3)644.4 (7)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.32 × 0.12 × 0.05
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2000)
Tmin, Tmax0.980, 0.994
No. of measured, independent and
observed [I > 2σ(I)] reflections
3378, 757, 505
Rint0.080
(sin θ/λ)max1)0.606
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.066, 0.153, 1.05
No. of reflections757
No. of parameters91
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.18, 0.17

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O2i0.932.353.205 (3)152.9
C6—H4···N1ii0.962.623.582 (3)177.4
Symmetry codes: (i) x+1, y1, z; (ii) x+1, y+1/2, z+3/2.
 

Acknowledgements

The authors thank the Shandong Distinguished Middle-Aged and Young Scientist Encouragement and the Reward Fund (No. 2006BS04006) for financial support.

References

First citationBoechat, N., Costa, J. C. S., Mendonca, J. S., Paes, K. C., Fernandes, E. L., Oliveira, P. S. M., Vasconcelos, T. R. A. & Souza, M. V. N. (2005). Synth. Commun. 35, 3187–3190.  Web of Science CrossRef CAS Google Scholar
First citationBruker (2000). SMART), SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDesiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford University Press.  Google Scholar
First citationKim, J. W., Choi, K. D., Lim, J. W., Lee, K. H. & Lee, S. H. (2004). PCT Int. Appl. WO 2004048369.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
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