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Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): o2902.
Published online 2009 October 28. doi:  10.1107/S1600536809043451
PMCID: PMC2971415

Methyl pyrazine-2-carboxyl­ate

Abstract

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 [triangle]). For reduction of heteroaromatic esters, see: Boechat et al. (2005 [triangle]). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999 [triangle]).

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Object name is e-65-o2902-scheme1.jpg

Experimental

Crystal data

  • C6H6N2O2
  • M r = 138.13
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2902-efi1.jpg
  • 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 [triangle]) T min = 0.980, T max = 0.994
  • 3378 measured reflections
  • 757 independent reflections
  • 505 reflections with I > 2σ(I)
  • R int = 0.080

Refinement

  • R[F 2 > 2σ(F 2)] = 0.066
  • wR(F 2) = 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

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

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809043451/im2150sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809043451/im2150Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

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

supplementary crystallographic information

Comment

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].

Experimental

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

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.

Figures

Fig. 1.
The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms.
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).

Crystal data

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

Bruker SMART CCD area-detector diffractometer757 independent reflections
Radiation source: fine-focus sealed tube505 reflections with I > 2σ(I)
graphiteRint = 0.080
π and ω scansθmax = 25.5°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2000)h = −4→4
Tmin = 0.980, Tmax = 0.994k = −7→8
3378 measured reflectionsl = −30→22

Refinement

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 = 1.05w = 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

Special details

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)

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*
H6−0.10491.00890.76430.096*
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)
O2−0.0298 (4)0.97530 (17)0.87108 (5)0.0690 (5)

Atomic displacement parameters (Å2)

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, °)

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, °)

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, y−1, z; (ii) −x+1, y+1/2, −z+3/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IM2150).

References

  • 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.
  • Bruker (2000). SMART), SAINT-Plus and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond Oxford University Press.
  • Kim, J. W., Choi, K. D., Lim, J. W., Lee, K. H. & Lee, S. H. (2004). PCT Int. Appl. WO 2004048369.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography