organic compounds
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
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). For reduction of heteroaromatic see: Boechat et al. (2005). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).
Supporting information
https://doi.org/10.1107/S1600536809043451/im2150sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809043451/im2150Isup2.hkl
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%.
Since the compound itself is achiral and in the absence of significant
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.Heteroaromatic
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
(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
see: Boechat et al. (2005). For a description of weak hydrogen bonds, see: Desiraju & Steiner (1999).Data collection: SMART (Bruker, 2000); cell
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).C6H6N2O2 | F(000) = 288 |
Mr = 138.13 | Dx = 1.424 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 378 reflections |
a = 3.865 (2) Å | θ = 1.6–25.5° |
b = 6.690 (4) Å | µ = 0.11 mm−1 |
c = 24.92 (2) Å | T = 298 K |
V = 644.4 (7) Å3 | Needle, colourless |
Z = 4 | 0.32 × 0.12 × 0.05 mm |
Bruker SMART CCD area-detector diffractometer | 757 independent reflections |
Radiation source: fine-focus sealed tube | 505 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.080 |
π and ω scans | θmax = 25.5°, θmin = 1.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −4→4 |
Tmin = 0.980, Tmax = 0.994 | k = −7→8 |
3378 measured reflections | l = −30→22 |
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)] = 0.066 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.153 | H-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 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
C6H6N2O2 | V = 644.4 (7) Å3 |
Mr = 138.13 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 3.865 (2) Å | µ = 0.11 mm−1 |
b = 6.690 (4) Å | T = 298 K |
c = 24.92 (2) Å | 0.32 × 0.12 × 0.05 mm |
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 = 0.994 | Rint = 0.080 |
3378 measured reflections |
R[F2 > 2σ(F2)] = 0.066 | 0 restraints |
wR(F2) = 0.153 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.18 e Å−3 |
757 reflections | Δρmin = −0.17 e Å−3 |
91 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.2013 (5) | 0.6623 (3) | 0.93604 (7) | 0.0546 (6) | |
H1 | 0.0959 | 0.7714 | 0.9524 | 0.065* | |
C2 | 0.2602 (4) | 0.6690 (2) | 0.88246 (6) | 0.0371 (5) | |
C3 | 0.5035 (6) | 0.3674 (2) | 0.88599 (7) | 0.0561 (6) | |
H2 | 0.6133 | 0.2594 | 0.8698 | 0.067* | |
C4 | 0.4367 (6) | 0.3607 (3) | 0.93986 (7) | 0.0604 (6) | |
H3 | 0.4999 | 0.2470 | 0.9589 | 0.072* | |
C5 | 0.1459 (4) | 0.8493 (2) | 0.85163 (6) | 0.0395 (5) | |
C6 | 0.1405 (5) | 1.0165 (2) | 0.76991 (8) | 0.0642 (7) | |
H4 | 0.2569 | 1.0139 | 0.7359 | 0.096* | |
H5 | 0.1955 | 1.1385 | 0.7883 | 0.096* | |
H6 | −0.1049 | 1.0089 | 0.7643 | 0.096* | |
N1 | 0.4157 (4) | 0.52391 (19) | 0.85628 (6) | 0.0479 (5) | |
N2 | 0.2869 (5) | 0.5082 (2) | 0.96584 (6) | 0.0665 (6) | |
O1 | 0.2516 (3) | 0.84861 (17) | 0.80180 (4) | 0.0514 (4) | |
O2 | −0.0298 (4) | 0.97530 (17) | 0.87108 (5) | 0.0690 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0681 (13) | 0.0448 (11) | 0.0508 (10) | 0.0017 (11) | 0.0019 (11) | 0.0020 (10) |
C2 | 0.0335 (8) | 0.0284 (8) | 0.0494 (10) | 0.0006 (8) | 0.0029 (9) | 0.0011 (8) |
C3 | 0.0621 (12) | 0.0330 (9) | 0.0733 (12) | 0.0112 (11) | −0.0098 (11) | 0.0040 (10) |
C4 | 0.0677 (13) | 0.0406 (10) | 0.0728 (12) | 0.0014 (11) | −0.0187 (12) | 0.0199 (10) |
C5 | 0.0409 (10) | 0.0302 (8) | 0.0475 (10) | −0.0001 (9) | 0.0019 (9) | 0.0023 (9) |
C6 | 0.0719 (15) | 0.0541 (11) | 0.0666 (13) | 0.0086 (12) | −0.0045 (11) | 0.0180 (11) |
N1 | 0.0535 (9) | 0.0344 (7) | 0.0559 (9) | 0.0089 (8) | −0.0002 (8) | −0.0017 (8) |
N2 | 0.0891 (12) | 0.0549 (10) | 0.0554 (10) | 0.0024 (11) | −0.0065 (10) | 0.0083 (9) |
O1 | 0.0664 (8) | 0.0412 (6) | 0.0465 (7) | 0.0105 (7) | 0.0004 (7) | 0.0083 (6) |
O2 | 0.0935 (10) | 0.0428 (7) | 0.0705 (9) | 0.0264 (8) | 0.0187 (8) | −0.0033 (7) |
C1—N2 | 1.312 (2) | C4—N2 | 1.315 (3) |
C1—C2 | 1.355 (2) | C4—H3 | 0.9300 |
C1—H1 | 0.9300 | C5—O2 | 1.186 (2) |
C2—N1 | 1.315 (2) | C5—O1 | 1.307 (2) |
C2—C5 | 1.497 (2) | C6—O1 | 1.441 (2) |
C3—N1 | 1.327 (2) | C6—H4 | 0.9600 |
C3—C4 | 1.368 (3) | C6—H5 | 0.9600 |
C3—H2 | 0.9300 | C6—H6 | 0.9600 |
N2—C1—C2 | 122.76 (17) | O2—C5—O1 | 124.72 (15) |
N2—C1—H1 | 118.6 | O2—C5—C2 | 122.14 (15) |
C2—C1—H1 | 118.6 | O1—C5—C2 | 113.11 (14) |
N1—C2—C1 | 122.77 (15) | O1—C6—H4 | 109.5 |
N1—C2—C5 | 118.36 (15) | O1—C6—H5 | 109.5 |
C1—C2—C5 | 118.87 (15) | H4—C6—H5 | 109.5 |
N1—C3—C4 | 121.68 (17) | O1—C6—H6 | 109.5 |
N1—C3—H2 | 119.2 | H4—C6—H6 | 109.5 |
C4—C3—H2 | 119.2 | H5—C6—H6 | 109.5 |
N2—C4—C3 | 122.83 (17) | C2—N1—C3 | 114.99 (15) |
N2—C4—H3 | 118.6 | C1—N2—C4 | 114.94 (16) |
C3—C4—H3 | 118.6 | C5—O1—C6 | 115.33 (14) |
D—H···A | D—H | H···A | D···A | 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+1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C6H6N2O2 |
Mr | 138.13 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 3.865 (2), 6.690 (4), 24.92 (2) |
V (Å3) | 644.4 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.32 × 0.12 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.980, 0.994 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3378, 757, 505 |
Rint | 0.080 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.066, 0.153, 1.05 |
No. of reflections | 757 |
No. of parameters | 91 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.18, −0.17 |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H2···O2i | 0.93 | 2.35 | 3.205 (3) | 152.9 |
C6—H4···N1ii | 0.96 | 2.62 | 3.582 (3) | 177.4 |
Symmetry codes: (i) x+1, y−1, 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
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. Web of Science CrossRef CAS Google Scholar
Bruker (2000). SMART), SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford University Press. Google Scholar
Kim, J. W., Choi, K. D., Lim, J. W., Lee, K. H. & Lee, S. H. (2004). PCT Int. Appl. WO 2004048369. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
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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].