organic compounds
Diethyl pyrazine-2,5-dicarboxylate
aCollege of Materials Science and Engineering, Huaqiao University, Xiamen, Fujian 361021, People's Republic of China
*Correspondence e-mail: wws@hqu.edu.cn
The molecule of the title compound, C10H12N2O4, is located around an inversion center. The carboxylate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 2.76 (19)°. In the crystal, molecules are stacked along the c axis via weak C—H⋯O hydrogen bonds.
Related literature
For the structures of related compounds, see: Zhang et al. (2010); Cockriel et al. (2008).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 1997); cell SAINT (Bruker, 1999); data reduction: SAINT; 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
https://doi.org/10.1107/S1600536812028164/is5143sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812028164/is5143Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812028164/is5143Isup3.cml
The title compound was synthesized by dissolving 2,5-pyrazinedicarboxylic acid (2 g, 11.9 mmol) in 200 ml ethanol, while stirring 2 ml concentrated H2SO4 was added slowly. The solution was left to reflux for 12 h, then distillation under reduced pressure until no solution to outflow. The solution was made neutral with Na2CO3(aq), extracted with 30 ml ethyl acetate. Transparent crystals of the title compound were obtained by slow evaporation at room temperature for ten days.
H atoms were included in a riding model approximation with C—H = 0.93–0.97 Å, and with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(Cmehtyl) .
The structure of the title compound is illustrated in Fig. 1. The molecule of title compound, C10H12N2O4, is essentially planar and the carboxylate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 2.76 (19)°. The carboxyl C—O and C═O bonds are normal, while the bond angle of C—N═C are slightly larger than those in diisopropyl pyrazine-2,5-dicarboxylate (Zhang et al., 2010). The angle C3—O1—C4 of 116.05° is larger compared to the value of 115.05° in pyrazine-2,5-dicarboxylic acid dimethyl ester (Cockriel et al., 2008). The is stabilized via and week C—H···O hydrogen bonds (Fig. 2 and Table 1).
For the structures of related compounds, see: Zhang et al. (2010); Cockriel et al. (2008).
Data collection: SMART (Bruker, 1997); cell
SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); 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).C10H12N2O4 | F(000) = 236.0 |
Mr = 224.22 | Dx = 1.440 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 2994 reflections |
a = 12.284 (6) Å | θ = 4.0–28.5° |
b = 5.640 (3) Å | µ = 0.11 mm−1 |
c = 7.881 (4) Å | T = 173 K |
β = 108.713 (9)° | Plate, colourless |
V = 517.2 (5) Å3 | 0.7 × 0.3 × 0.05 mm |
Z = 2 |
Bruker SMART diffractometer | 1317 independent reflections |
Radiation source: fine-focus sealed tube | 1055 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω scans | θmax = 28.5°, θmin = 4.0° |
Absorption correction: multi-scan (SADABS; Sheldrick,1996) | h = −16→14 |
Tmin = 0.960, Tmax = 0.994 | k = −5→7 |
2994 measured reflections | l = −10→10 |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0606P)2 + 0.1472P] where P = (Fo2 + 2Fc2)/3 |
1317 reflections | (Δ/σ)max < 0.001 |
73 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.31 e Å−3 |
C10H12N2O4 | V = 517.2 (5) Å3 |
Mr = 224.22 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.284 (6) Å | µ = 0.11 mm−1 |
b = 5.640 (3) Å | T = 173 K |
c = 7.881 (4) Å | 0.7 × 0.3 × 0.05 mm |
β = 108.713 (9)° |
Bruker SMART diffractometer | 1317 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick,1996) | 1055 reflections with I > 2σ(I) |
Tmin = 0.960, Tmax = 0.994 | Rint = 0.031 |
2994 measured reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.21 e Å−3 |
1317 reflections | Δρmin = −0.31 e Å−3 |
73 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 | ||
N1 | 0.46961 (11) | −0.2315 (2) | 0.52651 (18) | 0.0275 (3) | |
O1 | 0.26007 (9) | 0.0921 (2) | 0.64425 (16) | 0.0308 (3) | |
O2 | 0.28072 (11) | −0.3005 (2) | 0.63126 (19) | 0.0401 (4) | |
C1 | 0.41208 (12) | −0.0450 (3) | 0.55512 (19) | 0.0241 (3) | |
C2 | 0.44174 (13) | 0.1860 (3) | 0.5289 (2) | 0.0265 (4) | |
H2A | 0.3986 | 0.3110 | 0.5507 | 0.032* | |
C3 | 0.31162 (13) | −0.1030 (3) | 0.6147 (2) | 0.0265 (4) | |
C4 | 0.16106 (15) | 0.0568 (3) | 0.7018 (3) | 0.0359 (4) | |
H4A | 0.1848 | 0.0010 | 0.8247 | 0.043* | |
H4B | 0.1102 | −0.0605 | 0.6266 | 0.043* | |
C5 | 0.10095 (15) | 0.2883 (3) | 0.6871 (2) | 0.0377 (4) | |
H5A | 0.0725 | 0.3356 | 0.5636 | 0.057* | |
H5B | 0.1537 | 0.4058 | 0.7549 | 0.057* | |
H5C | 0.0378 | 0.2732 | 0.7333 | 0.057* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0314 (7) | 0.0174 (6) | 0.0369 (7) | −0.0001 (5) | 0.0154 (6) | 0.0002 (5) |
O1 | 0.0289 (6) | 0.0234 (6) | 0.0457 (7) | 0.0012 (4) | 0.0199 (5) | 0.0006 (5) |
O2 | 0.0450 (8) | 0.0234 (7) | 0.0617 (9) | −0.0062 (5) | 0.0307 (6) | −0.0005 (6) |
C1 | 0.0256 (7) | 0.0211 (8) | 0.0256 (7) | −0.0009 (6) | 0.0080 (6) | −0.0005 (6) |
C2 | 0.0304 (8) | 0.0184 (7) | 0.0328 (8) | 0.0014 (6) | 0.0132 (6) | 0.0000 (6) |
C3 | 0.0284 (8) | 0.0212 (8) | 0.0304 (8) | −0.0010 (6) | 0.0104 (6) | 0.0007 (6) |
C4 | 0.0330 (9) | 0.0337 (9) | 0.0493 (10) | 0.0000 (7) | 0.0247 (8) | 0.0048 (8) |
C5 | 0.0330 (9) | 0.0410 (11) | 0.0450 (10) | 0.0046 (7) | 0.0208 (8) | 0.0018 (8) |
N1—C2i | 1.322 (2) | C2—H2A | 0.9300 |
N1—C1 | 1.326 (2) | C4—C5 | 1.486 (3) |
O1—C3 | 1.3270 (19) | C4—H4A | 0.9700 |
O1—C4 | 1.442 (2) | C4—H4B | 0.9700 |
O2—C3 | 1.197 (2) | C5—H5A | 0.9600 |
C1—C2 | 1.386 (2) | C5—H5B | 0.9600 |
C1—C3 | 1.490 (2) | C5—H5C | 0.9600 |
C2i—N1—C1 | 116.31 (14) | O1—C4—H4A | 110.2 |
C3—O1—C4 | 116.04 (13) | C5—C4—H4A | 110.2 |
N1—C1—C2 | 122.69 (14) | O1—C4—H4B | 110.2 |
N1—C1—C3 | 114.83 (14) | C5—C4—H4B | 110.2 |
C2—C1—C3 | 122.47 (14) | H4A—C4—H4B | 108.5 |
N1i—C2—C1 | 121.00 (15) | C4—C5—H5A | 109.5 |
N1i—C2—H2A | 119.5 | C4—C5—H5B | 109.5 |
C1—C2—H2A | 119.5 | H5A—C5—H5B | 109.5 |
O2—C3—O1 | 124.49 (15) | C4—C5—H5C | 109.5 |
O2—C3—C1 | 124.19 (15) | H5A—C5—H5C | 109.5 |
O1—C3—C1 | 111.31 (13) | H5B—C5—H5C | 109.5 |
O1—C4—C5 | 107.59 (14) | ||
C2i—N1—C1—C2 | 0.1 (3) | N1—C1—C3—O2 | −2.3 (2) |
C2i—N1—C1—C3 | 179.07 (13) | C2—C1—C3—O2 | 176.70 (16) |
N1—C1—C2—N1i | −0.1 (3) | N1—C1—C3—O1 | 178.63 (13) |
C3—C1—C2—N1i | −178.99 (14) | C2—C1—C3—O1 | −2.4 (2) |
C4—O1—C3—O2 | 0.6 (2) | C3—O1—C4—C5 | −167.24 (14) |
C4—O1—C3—C1 | 179.71 (13) |
Symmetry code: (i) −x+1, −y, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4A···O2ii | 0.97 | 2.58 | 3.537 (3) | 168 |
Symmetry code: (ii) x, −y−1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C10H12N2O4 |
Mr | 224.22 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 12.284 (6), 5.640 (3), 7.881 (4) |
β (°) | 108.713 (9) |
V (Å3) | 517.2 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.7 × 0.3 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART |
Absorption correction | Multi-scan (SADABS; Sheldrick,1996) |
Tmin, Tmax | 0.960, 0.994 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2994, 1317, 1055 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.671 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.131, 1.07 |
No. of reflections | 1317 |
No. of parameters | 73 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.31 |
Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4A···O2i | 0.97 | 2.58 | 3.537 (3) | 168 |
Symmetry code: (i) x, −y−1/2, z+1/2. |
Acknowledgements
The authors are grateful for financial support from the National Science Foundation of Fujian Province of China (No. 2010 J01288) and the Fundamental Research Funds for the Central Universities (No. JB-JC1003).
References
Bruker (1997). SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (1999). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cockriel, D. L., McClain, J. M., Patel, K. C., Ullom, R., Hasley, T. R., Archibald, S. J. & Hubin, T. J. (2008). Inorg. Chem. Commun. 11, 1–4. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhang, X.-Q., Wu, W.-S., Wang, X.-Y. & Ma, J.-H. (2010). Acta Cryst. E66, o2206. Web of Science CSD CrossRef IUCr Journals Google Scholar
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The structure of the title compound is illustrated in Fig. 1. The molecule of title compound, C10H12N2O4, is essentially planar and the carboxylate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 2.76 (19)°. The carboxyl C—O and C═O bonds are normal, while the bond angle of C—N═C are slightly larger than those in diisopropyl pyrazine-2,5-dicarboxylate (Zhang et al., 2010). The angle C3—O1—C4 of 116.05° is larger compared to the value of 115.05° in pyrazine-2,5-dicarboxylic acid dimethyl ester (Cockriel et al., 2008). The crystal structure is stabilized via van der Waals forces and week C—H···O hydrogen bonds (Fig. 2 and Table 1).