6-Chloro-1,4-di­ethyl­quinoxaline-2,3(1H,4H)-dione

El Janati, A.; Kandri Rodi, Y.; Jasinski, J.P.; Kaur, M.; Ouzidan, Y.; Essassi, E.M.

doi:10.1107/S2414314617010525

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 2| Part 7| July 2017| x171052

https://doi.org/10.1107/S2414314617010525

Open

access

6-Chloro-1,4-diethylquinoxaline-2,3(1H,4H)-dione

Ali El Janati,^a ^* Youssef Kandri Rodi,^a Jerry P. Jasinski,^b Manpreet Kaur,^b Younes Ouzidan ^a and El Mokhtar Essassi ^c

^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: alieljanati@gmail.com

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 13 July 2017; accepted 16 July 2017; online 21 July 2017)

In the title compound, C₁₂H₁₃ClN₂O₂, the terminal C atoms of the ethyl groups deviate from the mean plane of the quinoxaline-2,3(1H,4H)-dione ring (r.m.s. deviation = 0.016 Å) in opposite directions by −1.451 (2) and 1.472 (2) Å. In the crystal, weak C—H⋯O interactions link the molecules into [100] chains and aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.6631 (9) Å] are also observed.

Keywords: quinoxaline; crystal structure; PTC.

CCDC reference: 1562478

Structure description

As a continuation of our studies of substituted quinoxaline derivatives (El Janati et al., 2017 ), we now report the synthesis and structure of the title compound (Fig. 1) prepared by the condensation reaction of 6-chloroquinoxaline-2,3(1H,4H)-dione with iodoethane.

Figure 1
The molecular structure showing 30% probability displacement ellipsoids for the non-H atoms.

The terminal C atoms of the ethyl groups deviate from the mean plane of the quinoxaline-2,3(1H,4H)-dione ring (r.m.s. deviation = 0.016 Å) in opposite directions, by −1.451 (2) and 1.472 (2) Å, for C10 and C12, respectively. In the crystal, weak C—H⋯O interactions link the molecules into [100] chains with O2 acting as a double acceptor (Table 1, Fig. 2). Aromatic π–π stacking interactions occur between the chains: Cg2⋯Cg2( $[{1\over 2}]$ − x,y,-z) = 3.6632 (2) Å and Cg1⋯Cg2( $[{1\over 2}]$ − x, $[{1\over 2}]$ − y, $[{1\over 2}]$ − z) = 3.9508 (2) Å, where Cg1 and Cg2 are the centroids of the N1/C1/C2/N2/C3/C8 and C3–C8 rings, respectively.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯O2ⁱ	0.93	2.53	3.440 (2)	167
C9—H9B⋯O2ⁱ	0.97	2.35	3.180 (2)	144
Symmetry code: (i) $[x-{\script{1\over 2}}, -y+1, z]$ .

Figure 2
The packing viewed along the c axis. Dashed lines indicate weak C—H⋯O interactions with atom O2 serving as a double acceptor, linking the molecules into [100] chains. H atoms not involved in the packing are omitted for clarity.

Synthesis and crystallization

To a solution of 6-chloro-1,4-dihydroquinoxaline-2,3-dione 0.30 g (1.53 mmol) in DMF (20 ml), were added 0.52 g (3.84 mmol) of potassium carbonate and 0.1 mmol of tetra-n-butyl ammonium. After 10 min of stirring, 3.85 mmol of iodoethane was added, then the mixture was allowed to stir at room temperature for 36 h. After filtration, the DMF was evaporated under reduced pressure and the residue obtained was dissolved in dichloromethane. The organic phase was dried over Na₂SO₄ and then concentrated. The mixture obtained was chromatographed on a silica gel column [eluent: hexane/ethyl acetate (3/1)]. Crystals were obtained when the solvent was allowed to evaporate.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₂H₁₃ClN₂O₂
M_r	252.69
Crystal system, space group	Monoclinic, I2/a
Temperature (K)	293
a, b, c (Å)	14.6454 (8), 12.0415 (5), 15.1149 (9)
β (°)	115.621 (7)
V (Å³)	2403.5 (3)
Z	8
Radiation type	Cu Kα
μ (mm⁻¹)	2.76
Crystal size (mm)	0.22 × 0.18 × 0.12

Data collection
Diffractometer	Rigaku, Oxford diffraction
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku Oxford Diffraction, 2015 $[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Americas, The Woodlands, Texas, USA.]$ )
T_min, T_max	0.749, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	4349, 2291, 1944
R_int	0.015
(sin θ/λ)_max (Å⁻¹)	0.614

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.128, 1.03
No. of reflections	2291
No. of parameters	156
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.31
Computer programs: CrysAlis PRO (Rigaku Oxford Diffraction, 2015 $[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Americas, The Woodlands, Texas, USA.]$ ), SHELXT2014 (Sheldrick, 2015b ), SHELXL (Sheldrick, 2015a ) and OLEX2 (Dolomanov et al., 2009 ).

Structural data

CCDC reference: 1562478

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314617010525/hb4159sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617010525/hb4159Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314617010525/hb4159Isup3.cdx

Supporting information file. DOI: https://doi.org/10.1107/S2414314617010525/hb4159Isup4.cml

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); cell refinement: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); data reduction: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015b); program(s) used to refine structure: SHELXL (Sheldrick, 2015a); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

6-Chloro-1,4-diethylquinoxaline-2,3(1H,4H)-dione top

Crystal data top

C₁₂H₁₃ClN₂O₂	F(000) = 1056
M_r = 252.69	D_x = 1.397 Mg m⁻³
Monoclinic, I2/a	Cu Kα radiation, λ = 1.54184 Å
a = 14.6454 (8) Å	Cell parameters from 1748 reflections
b = 12.0415 (5) Å	θ = 3.5–71.4°
c = 15.1149 (9) Å	µ = 2.76 mm⁻¹
β = 115.621 (7)°	T = 293 K
V = 2403.5 (3) Å³	Irregular, orange
Z = 8	0.22 × 0.18 × 0.12 mm

Data collection top

Rigaku, Oxford diffraction diffractometer	2291 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source	1944 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.015
Detector resolution: 16.0416 pixels mm^-1	θ_max = 71.3°, θ_min = 4.9°
ω scans	h = −15→17
Absorption correction: multi-scan (CrysAlis PRO; Rigaku Oxford Diffraction, 2015)	k = −14→14
T_min = 0.749, T_max = 1.000	l = −16→18
4349 measured reflections

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.045	H-atom parameters constrained
wR(F²) = 0.128	w = 1/[σ²(F_o²) + (0.0765P)² + 0.5895P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
2291 reflections	Δρ_max = 0.23 e Å⁻³
156 parameters	Δρ_min = −0.31 e Å⁻³
0 restraints

Special details top

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 calculated positions and refined using the riding model with C—H bond lengths of 0.93 Å (CH) or 0.97 Å (CH₂) or 0.96 Å (CH₃). Isotropic displacement parameters for these atoms were set to 1.2 (CH) or 1.5 (CH₃) times U_eq of the parent atom. Idealized Me groups were refined as rotating groups.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	0.13648 (4)	0.04185 (5)	0.36551 (4)	0.0703 (2)
O1	0.45160 (11)	0.58336 (12)	0.38236 (13)	0.0645 (4)
O2	0.56068 (10)	0.39761 (13)	0.40065 (12)	0.0646 (4)
N1	0.31793 (10)	0.48193 (12)	0.37493 (10)	0.0429 (3)
N2	0.42883 (10)	0.28937 (12)	0.38566 (10)	0.0429 (3)
C1	0.41348 (13)	0.49391 (16)	0.38203 (13)	0.0464 (4)
C2	0.47412 (13)	0.38917 (16)	0.39038 (13)	0.0465 (4)
C3	0.33032 (12)	0.28080 (14)	0.37896 (10)	0.0392 (4)
C4	0.28666 (13)	0.17761 (15)	0.37675 (11)	0.0446 (4)
H4	0.3225	0.1128	0.3799	0.054*
C5	0.18971 (14)	0.17216 (16)	0.36987 (12)	0.0484 (4)
C6	0.13456 (13)	0.26574 (18)	0.36620 (12)	0.0496 (4)
H6	0.0696	0.2601	0.3623	0.059*
C7	0.17739 (13)	0.36817 (16)	0.36843 (12)	0.0454 (4)
H7	0.1408	0.4321	0.3661	0.054*
C8	0.27497 (12)	0.37745 (15)	0.37412 (10)	0.0392 (4)
C9	0.25998 (14)	0.58452 (16)	0.36690 (15)	0.0525 (4)
H9A	0.3067	0.6458	0.3947	0.063*
H9B	0.2212	0.5762	0.4047	0.063*
C10	0.18908 (18)	0.6114 (2)	0.26220 (18)	0.0694 (6)
H10A	0.2268	0.6166	0.2239	0.104*
H10B	0.1561	0.6810	0.2599	0.104*
H10C	0.1392	0.5538	0.2361	0.104*
C11	0.49092 (14)	0.18977 (17)	0.39550 (14)	0.0514 (4)
H11A	0.5418	0.2065	0.3725	0.062*
H11B	0.4482	0.1309	0.3547	0.062*
C12	0.54246 (17)	0.15049 (17)	0.50063 (16)	0.0628 (5)
H12A	0.5870	0.0899	0.5055	0.094*
H12B	0.4923	0.1262	0.5213	0.094*
H12C	0.5809	0.2104	0.5418	0.094*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0777 (4)	0.0587 (3)	0.0866 (4)	−0.0233 (2)	0.0469 (3)	−0.0045 (2)
O1	0.0571 (8)	0.0507 (8)	0.0965 (11)	−0.0130 (6)	0.0433 (8)	−0.0084 (7)
O2	0.0429 (7)	0.0682 (9)	0.0922 (11)	−0.0037 (6)	0.0380 (7)	0.0008 (8)
N1	0.0392 (7)	0.0452 (8)	0.0479 (7)	−0.0025 (6)	0.0221 (6)	−0.0040 (6)
N2	0.0403 (7)	0.0482 (8)	0.0447 (7)	−0.0005 (6)	0.0225 (6)	−0.0036 (6)
C1	0.0422 (8)	0.0493 (10)	0.0517 (9)	−0.0068 (7)	0.0242 (7)	−0.0054 (7)
C2	0.0402 (8)	0.0550 (10)	0.0494 (9)	−0.0019 (7)	0.0241 (7)	−0.0016 (7)
C3	0.0392 (7)	0.0481 (9)	0.0334 (7)	−0.0039 (7)	0.0186 (6)	−0.0033 (6)
C4	0.0506 (9)	0.0462 (9)	0.0419 (8)	−0.0024 (7)	0.0245 (7)	−0.0019 (7)
C5	0.0524 (9)	0.0551 (10)	0.0430 (8)	−0.0154 (8)	0.0256 (7)	−0.0030 (7)
C6	0.0434 (8)	0.0630 (11)	0.0488 (9)	−0.0078 (8)	0.0261 (7)	0.0008 (8)
C7	0.0405 (8)	0.0559 (10)	0.0447 (8)	0.0003 (7)	0.0231 (7)	0.0011 (7)
C8	0.0392 (8)	0.0485 (9)	0.0327 (7)	−0.0043 (7)	0.0182 (6)	−0.0026 (6)
C9	0.0465 (9)	0.0466 (9)	0.0669 (11)	−0.0023 (8)	0.0269 (8)	−0.0100 (8)
C10	0.0692 (13)	0.0590 (12)	0.0808 (14)	0.0115 (10)	0.0331 (11)	0.0122 (11)
C11	0.0481 (9)	0.0526 (10)	0.0605 (10)	0.0039 (8)	0.0302 (8)	−0.0069 (8)
C12	0.0639 (12)	0.0498 (10)	0.0673 (12)	0.0076 (9)	0.0214 (10)	−0.0022 (9)

Geometric parameters (Å, º) top

Cl1—C5	1.7407 (19)	C6—C7	1.378 (3)
O1—C1	1.212 (2)	C7—H7	0.9300
O2—C2	1.213 (2)	C7—C8	1.399 (2)
N1—C1	1.364 (2)	C9—H9A	0.9700
N1—C8	1.404 (2)	C9—H9B	0.9700
N1—C9	1.474 (2)	C9—C10	1.505 (3)
N2—C2	1.359 (2)	C10—H10A	0.9600
N2—C3	1.406 (2)	C10—H10B	0.9600
N2—C11	1.473 (2)	C10—H10C	0.9600
C1—C2	1.516 (3)	C11—H11A	0.9700
C3—C4	1.391 (2)	C11—H11B	0.9700
C3—C8	1.402 (2)	C11—C12	1.510 (3)
C4—H4	0.9300	C12—H12A	0.9600
C4—C5	1.380 (2)	C12—H12B	0.9600
C5—C6	1.373 (3)	C12—H12C	0.9600
C6—H6	0.9300

C1—N1—C8	122.40 (15)	C3—C8—N1	119.77 (14)
C1—N1—C9	116.90 (15)	C7—C8—N1	120.93 (16)
C8—N1—C9	120.69 (14)	C7—C8—C3	119.30 (16)
C2—N2—C3	122.07 (15)	N1—C9—H9A	109.2
C2—N2—C11	116.65 (14)	N1—C9—H9B	109.2
C3—N2—C11	121.12 (14)	N1—C9—C10	112.20 (16)
O1—C1—N1	123.32 (18)	H9A—C9—H9B	107.9
O1—C1—C2	119.13 (16)	C10—C9—H9A	109.2
N1—C1—C2	117.55 (16)	C10—C9—H9B	109.2
O2—C2—N2	122.68 (18)	C9—C10—H10A	109.5
O2—C2—C1	118.88 (17)	C9—C10—H10B	109.5
N2—C2—C1	118.43 (15)	C9—C10—H10C	109.5
C4—C3—N2	120.94 (15)	H10A—C10—H10B	109.5
C4—C3—C8	119.39 (15)	H10A—C10—H10C	109.5
C8—C3—N2	119.67 (15)	H10B—C10—H10C	109.5
C3—C4—H4	120.3	N2—C11—H11A	109.3
C5—C4—C3	119.45 (17)	N2—C11—H11B	109.3
C5—C4—H4	120.3	N2—C11—C12	111.54 (15)
C4—C5—Cl1	118.37 (15)	H11A—C11—H11B	108.0
C6—C5—Cl1	119.48 (14)	C12—C11—H11A	109.3
C6—C5—C4	122.15 (17)	C12—C11—H11B	109.3
C5—C6—H6	120.7	C11—C12—H12A	109.5
C5—C6—C7	118.69 (16)	C11—C12—H12B	109.5
C7—C6—H6	120.7	C11—C12—H12C	109.5
C6—C7—H7	119.5	H12A—C12—H12B	109.5
C6—C7—C8	121.02 (17)	H12A—C12—H12C	109.5
C8—C7—H7	119.5	H12B—C12—H12C	109.5

Cl1—C5—C6—C7	−179.16 (13)	C4—C3—C8—N1	−179.12 (14)
O1—C1—C2—O2	2.5 (3)	C4—C3—C8—C7	0.8 (2)
O1—C1—C2—N2	−177.21 (17)	C4—C5—C6—C7	0.7 (3)
N1—C1—C2—O2	−177.15 (16)	C5—C6—C7—C8	0.1 (2)
N1—C1—C2—N2	3.1 (2)	C6—C7—C8—N1	179.05 (15)
N2—C3—C4—C5	−179.83 (13)	C6—C7—C8—C3	−0.9 (2)
N2—C3—C8—N1	0.7 (2)	C8—N1—C1—O1	179.63 (17)
N2—C3—C8—C7	−179.38 (13)	C8—N1—C1—C2	−0.7 (2)
C1—N1—C8—C3	−1.2 (2)	C8—N1—C9—C10	−81.9 (2)
C1—N1—C8—C7	178.90 (14)	C8—C3—C4—C5	0.0 (2)
C1—N1—C9—C10	97.43 (19)	C9—N1—C1—O1	0.3 (3)
C2—N2—C3—C4	−178.34 (15)	C9—N1—C1—C2	179.98 (15)
C2—N2—C3—C8	1.8 (2)	C9—N1—C8—C3	178.14 (14)
C2—N2—C11—C12	93.20 (19)	C9—N1—C8—C7	−1.8 (2)
C3—N2—C2—O2	176.57 (16)	C11—N2—C2—O2	1.1 (3)
C3—N2—C2—C1	−3.7 (2)	C11—N2—C2—C1	−179.15 (15)
C3—N2—C11—C12	−82.3 (2)	C11—N2—C3—C4	−3.1 (2)
C3—C4—C5—Cl1	179.10 (12)	C11—N2—C3—C8	177.12 (14)
C3—C4—C5—C6	−0.8 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O2ⁱ	0.93	2.53	3.440 (2)	167
C9—H9B···O2ⁱ	0.97	2.35	3.180 (2)	144

Symmetry code: (i) x−1/2, −y+1, z.

Acknowledgements

JPJ acknowledges the NSF–MRI program (Grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.

References

Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
El Janati, A., Kandri Rodi, Y., Jasinski, J. P., Kaur, M., Ouzidan, Y. & Essassi, E. M. (2017). IUCrData, 2, x170901. Google Scholar
Rigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Americas, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.