organic compounds
7-Bromo-1,4-bis(prop-2-ynyl)pyrido[2,3-b]pyrazine-2,3(1H,4H)-dione
aLaboratoire de Chimie Organique Appliquée, Faculté des Sciences et Techniques, Université Sidi Mohammed Ben Abdellah, Fès, Morocco, bDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA, and cLaboratoire de Chimie Organique Hétérocyclique, Pôle de Compétences Pharmacochimie, Mohammed V University in Rabat, BP 1014, Avenue Ibn Batouta, Rabat, Morocco
*Correspondence e-mail: sikine.meriem@gmail.com
In the title compound, C13H8BrN3O2, the pyrido-pyrazine fused-ring system is essentially planar (r.m.s. deviation = 0.061 Å). The prop-2-ynyl moieties are twisted away from the ring system in opposite directions. In the crystal, a single weak C—H⋯O interaction generates [010] chains and aromatic π–π stacking interactions between the pyridine rings are observed.
Keywords: crystal structure; pyrido[2,3-b]pyrazine.
CCDC reference: 1823956
Structure description
Heterocycles containing a pyrido-pyrazine grouping possess useful medicinal properties (Zhang et al., 2012). They may also exhibit good inhibitory action on the corrosion of metals (Ouzidan et al., 2016). As part of our studies in this area, we now report the synthesis of a new pyrido[2,3-b]pyrazine and its crystal structure.
The title compound crystallizes with one molecule in the ). The pyrido-pyrazine moiety is essentially planar: the dihedral angle between the fused rings is 4.7 (6)°. The prop-2-ynyl moieties are twisted away from the mean plane of the pyrido-pyrazine ring [C8—C9—N2 = 114.0 (2)° and C12—C11—N1 = 110.1 (3)°] to avoid steric repulsion. In the crystal, a single weak C6—H6⋯O2 interaction links the molecules into [010] chains (Fig. 2 and Table 1). In addition, weak π–π stacking between the pyridine rings is observed [centroid–centroid separation = 3.7089 (2) Å].
(Fig. 1Synthesis and crystallization
To a solution of 7-bromopyrido[2,3-b]pyrazine-2,3(1H,4H)-dione (0.2 g, 0.826 mmol), K2CO3 (0.456 g, 3.304 mmol), tetra-n-bromide butyl ammonium (0.1 mmol) in DMF (15 ml) was added propargyl bromide (0.213 ml, 1.790 mmol), and the mixture was stirred for 24 h at room temperature. After the solvent was evaporated under reduced pressure, the product was isolated by on a silica gel column with ethyl acetate/hexane (1 /3) as the Red crystals were isolated when the solvent was allowed to evaporate (yield = 18%, m.p. 449 K).
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1823956
https://doi.org/10.1107/S2414314618002663/hb4210sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618002663/hb4210Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314618002663/hb4210Isup3.cdx
Supporting information file. DOI: https://doi.org/10.1107/S2414314618002663/hb4210Isup4.cml
Data collection: CrysAlis PRO (Rigaku OD, 2015); cell
CrysAlis PRO (Rigaku OD, 2015); data reduction: CrysAlis PRO (Rigaku OD, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).C13H8BrN3O2 | F(000) = 632 |
Mr = 318.13 | Dx = 1.704 Mg m−3 |
Monoclinic, P21/c | Cu Kα radiation, λ = 1.54184 Å |
a = 10.1922 (5) Å | Cell parameters from 1740 reflections |
b = 17.347 (1) Å | θ = 4.3–71.4° |
c = 7.0216 (4) Å | µ = 4.55 mm−1 |
β = 92.382 (5)° | T = 293 K |
V = 1240.38 (12) Å3 | Prism, red |
Z = 4 | 0.22 × 0.16 × 0.1 mm |
Rigaku Oxford Diffraction model name? diffractometer | 2361 independent reflections |
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source | 1994 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
Detector resolution: 16.0416 pixels mm-1 | θmax = 71.3°, θmin = 4.3° |
ω scans | h = −12→9 |
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015) | k = −20→18 |
Tmin = 0.428, Tmax = 1.000 | l = −8→7 |
4477 measured reflections |
Refinement on F2 | Primary atom site location: dual |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.036 | H-atom parameters constrained |
wR(F2) = 0.101 | w = 1/[σ2(Fo2) + (0.0557P)2 + 0.1537P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max < 0.001 |
2361 reflections | Δρmax = 0.50 e Å−3 |
172 parameters | Δρmin = −0.43 e Å−3 |
0 restraints |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. All the H atoms were placed in their calculated positions and then refined using a riding model with bond lengths of 0.93 Å (CH) or 0.97 Å (CH2). Isotropic displacement parameters for all these atoms were set to 1.2 (CH, CH2) times Ueq of the parent atom. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.11401 (3) | 0.16664 (2) | 0.36163 (5) | 0.05288 (15) | |
O1 | 0.6397 (2) | 0.49748 (14) | 0.1531 (4) | 0.0559 (6) | |
O2 | 0.4267 (3) | 0.56084 (13) | 0.3097 (4) | 0.0620 (7) | |
N1 | 0.5551 (2) | 0.37741 (14) | 0.1875 (3) | 0.0396 (5) | |
N2 | 0.3293 (2) | 0.44352 (13) | 0.3284 (3) | 0.0363 (5) | |
N3 | 0.4718 (2) | 0.25464 (14) | 0.2338 (3) | 0.0402 (5) | |
C1 | 0.5508 (3) | 0.45577 (17) | 0.2002 (4) | 0.0416 (6) | |
C2 | 0.4292 (3) | 0.49169 (17) | 0.2831 (4) | 0.0419 (6) | |
C3 | 0.3366 (2) | 0.36362 (15) | 0.3063 (4) | 0.0325 (5) | |
C4 | 0.2339 (3) | 0.31484 (16) | 0.3433 (4) | 0.0370 (5) | |
H4 | 0.1537 | 0.3342 | 0.3800 | 0.044* | |
C5 | 0.2537 (3) | 0.23636 (15) | 0.3243 (4) | 0.0373 (5) | |
C6 | 0.3740 (3) | 0.20755 (16) | 0.2754 (4) | 0.0411 (6) | |
H6 | 0.3869 | 0.1545 | 0.2715 | 0.049* | |
C7 | 0.4528 (3) | 0.32983 (15) | 0.2449 (4) | 0.0347 (5) | |
C8 | 0.2161 (3) | 0.47795 (16) | 0.4219 (4) | 0.0422 (6) | |
H8A | 0.2010 | 0.4495 | 0.5379 | 0.051* | |
H8B | 0.2379 | 0.5306 | 0.4578 | 0.051* | |
C9 | 0.0952 (3) | 0.47845 (17) | 0.3036 (5) | 0.0436 (6) | |
C10 | −0.0066 (3) | 0.4782 (2) | 0.2184 (5) | 0.0535 (8) | |
H10 | −0.0871 | 0.4780 | 0.1511 | 0.064* | |
C11 | 0.6748 (3) | 0.34154 (19) | 0.1177 (5) | 0.0507 (7) | |
H11A | 0.6521 | 0.2944 | 0.0499 | 0.061* | |
H11B | 0.7160 | 0.3762 | 0.0297 | 0.061* | |
C12 | 0.7673 (3) | 0.32418 (18) | 0.2785 (6) | 0.0524 (8) | |
C13 | 0.8389 (4) | 0.3114 (3) | 0.4095 (7) | 0.0715 (11) | |
H13 | 0.8958 | 0.3012 | 0.5135 | 0.086* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0547 (2) | 0.0393 (2) | 0.0645 (2) | −0.01276 (13) | 0.00117 (15) | 0.00276 (13) |
O1 | 0.0480 (12) | 0.0521 (13) | 0.0681 (15) | −0.0138 (10) | 0.0080 (10) | 0.0030 (11) |
O2 | 0.0639 (14) | 0.0322 (11) | 0.0909 (19) | −0.0061 (10) | 0.0152 (13) | −0.0050 (11) |
N1 | 0.0349 (11) | 0.0403 (12) | 0.0438 (13) | 0.0003 (9) | 0.0039 (9) | −0.0007 (10) |
N2 | 0.0386 (11) | 0.0293 (10) | 0.0410 (12) | 0.0025 (9) | 0.0029 (9) | −0.0028 (9) |
N3 | 0.0409 (12) | 0.0361 (11) | 0.0433 (12) | 0.0066 (9) | −0.0015 (9) | −0.0036 (10) |
C1 | 0.0403 (14) | 0.0433 (15) | 0.0411 (14) | −0.0040 (12) | −0.0014 (11) | 0.0012 (12) |
C2 | 0.0422 (14) | 0.0343 (14) | 0.0491 (16) | −0.0040 (11) | 0.0006 (11) | −0.0014 (11) |
C3 | 0.0363 (12) | 0.0305 (12) | 0.0306 (12) | 0.0012 (10) | −0.0014 (9) | 0.0015 (10) |
C4 | 0.0371 (13) | 0.0359 (13) | 0.0380 (13) | 0.0023 (11) | 0.0020 (10) | −0.0004 (11) |
C5 | 0.0449 (14) | 0.0310 (13) | 0.0357 (13) | −0.0036 (11) | −0.0029 (10) | 0.0014 (10) |
C6 | 0.0495 (15) | 0.0290 (13) | 0.0443 (15) | 0.0032 (11) | −0.0052 (12) | −0.0022 (11) |
C7 | 0.0356 (12) | 0.0340 (13) | 0.0341 (13) | 0.0013 (10) | −0.0020 (9) | −0.0020 (10) |
C8 | 0.0473 (15) | 0.0339 (13) | 0.0460 (15) | 0.0052 (11) | 0.0071 (12) | −0.0077 (11) |
C9 | 0.0450 (16) | 0.0376 (14) | 0.0491 (16) | 0.0085 (11) | 0.0107 (12) | 0.0009 (12) |
C10 | 0.0498 (18) | 0.0539 (18) | 0.0571 (19) | 0.0096 (14) | 0.0045 (14) | −0.0032 (15) |
C11 | 0.0410 (15) | 0.0528 (18) | 0.0590 (19) | 0.0034 (12) | 0.0115 (13) | −0.0033 (14) |
C12 | 0.0348 (14) | 0.0452 (16) | 0.078 (2) | −0.0002 (12) | 0.0109 (15) | 0.0023 (15) |
C13 | 0.0465 (19) | 0.074 (3) | 0.094 (3) | 0.0025 (18) | −0.004 (2) | 0.012 (2) |
Br1—C5 | 1.894 (3) | C4—H4 | 0.9300 |
O1—C1 | 1.217 (4) | C4—C5 | 1.384 (4) |
O2—C2 | 1.214 (4) | C5—C6 | 1.381 (4) |
N1—C1 | 1.363 (4) | C6—H6 | 0.9300 |
N1—C7 | 1.402 (4) | C8—H8A | 0.9700 |
N1—C11 | 1.472 (4) | C8—H8B | 0.9700 |
N2—C2 | 1.365 (4) | C8—C9 | 1.457 (5) |
N2—C3 | 1.397 (3) | C9—C10 | 1.176 (5) |
N2—C8 | 1.477 (3) | C10—H10 | 0.9300 |
N3—C6 | 1.331 (4) | C11—H11A | 0.9700 |
N3—C7 | 1.322 (4) | C11—H11B | 0.9700 |
C1—C2 | 1.524 (4) | C11—C12 | 1.472 (5) |
C3—C4 | 1.379 (4) | C12—C13 | 1.172 (6) |
C3—C7 | 1.405 (4) | C13—H13 | 0.9300 |
C1—N1—C7 | 122.8 (2) | N3—C6—C5 | 120.9 (2) |
C1—N1—C11 | 118.2 (2) | N3—C6—H6 | 119.5 |
C7—N1—C11 | 118.9 (2) | C5—C6—H6 | 119.5 |
C2—N2—C3 | 122.5 (2) | N1—C7—C3 | 119.3 (2) |
C2—N2—C8 | 117.4 (2) | N3—C7—N1 | 116.8 (2) |
C3—N2—C8 | 119.8 (2) | N3—C7—C3 | 123.9 (3) |
C7—N3—C6 | 118.7 (2) | N2—C8—H8A | 108.8 |
O1—C1—N1 | 123.3 (3) | N2—C8—H8B | 108.8 |
O1—C1—C2 | 119.2 (3) | H8A—C8—H8B | 107.7 |
N1—C1—C2 | 117.5 (2) | C9—C8—N2 | 114.0 (2) |
O2—C2—N2 | 123.2 (3) | C9—C8—H8A | 108.8 |
O2—C2—C1 | 119.0 (3) | C9—C8—H8B | 108.8 |
N2—C2—C1 | 117.7 (2) | C10—C9—C8 | 175.8 (3) |
N2—C3—C7 | 119.9 (2) | C9—C10—H10 | 180.0 |
C4—C3—N2 | 122.9 (2) | N1—C11—H11A | 109.6 |
C4—C3—C7 | 117.3 (2) | N1—C11—H11B | 109.6 |
C3—C4—H4 | 121.0 | H11A—C11—H11B | 108.1 |
C3—C4—C5 | 118.1 (2) | C12—C11—N1 | 110.1 (3) |
C5—C4—H4 | 121.0 | C12—C11—H11A | 109.6 |
C4—C5—Br1 | 120.1 (2) | C12—C11—H11B | 109.6 |
C6—C5—Br1 | 118.9 (2) | C13—C12—C11 | 178.3 (4) |
C6—C5—C4 | 121.0 (3) | C12—C13—H13 | 180.0 |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···O2i | 0.93 | 2.58 | 3.326 (4) | 137 |
Symmetry code: (i) −x+1, y−1/2, −z+1/2. |
Funding information
JPJ acknowledges the NSF-MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.
References
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