organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoIUCrDATA
ISSN: 2414-3146

1,4-Di­hexyl-1,2,3,4-tetra­hydro­quinoxaline-2,3-dione

aLaboratoire de Chimie Organique Hétérocyclique, Centre de Recherche des Sciences des Médicaments, URAC 21, Pôle de Compétence Pharmacochimie, Av Ibn Battouta, BP 1014, Faculté des Sciences, Université Mohammed V, Rabat, Morocco, and bDepartment of Chemistry, Tulane University, New Orleans, LA 70118, USA
*Correspondence e-mail: elbourakadi25@gmail.com

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 3 July 2017; accepted 8 July 2017; online 13 July 2017)

The title compound, C20H30N2O2, has crystallographically imposed C2 symmetry; the hexyl side chain adopts a tttg (t = trans and g = gauche) conformation. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into chains extending along the b-axis direction. These chains pack to form zigzag sheets lying parallel to (101).

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

This work was carried out in a continuation of our previous work on the synthesis and crystal structures of new quinoxaline-2,3-dione derivatives (Ferfra et al., 2001[Ferfra, S., Ahabchane, N. H., Mustaphi, N. E., Essassi, E. M., Bellan, J. & Pierrot, M. (2001). Phosphorus Sulfur Silicon, 175, 169-181.]; El Bourakadi et al., 2017a[El Bourakadi, K., El Bakri, Y., Sebhaoui, J., Rayni, I., Essassi, E. M. & Mague, J. T. (2017a). IUCrData, 2, x170520.],b[El Bourakadi, K., El Bakri, Y., Sebhaoui, J., Rayni, I., Essassi, E. M. & Mague, J. T. (2017b). IUCrData, 2, x170656.]).

The title mol­ecule (Fig. 1[link]) has crystallographically imposed C2 rotation symmetry. In the bicyclic unit, the dihedral angle between the two rings is 3.64 (7)°. The n-hexyl side chain adopts a tttg (t = trans and g = gauche) conformation, as indicated by the following torsion angles: N1—C5—C6—C7 = 178.85 (13)°, C5—C6—C7—C8 = −179.63 (15)°, C6—C7—C8—C9 = −179.30 (16)°, and C7—C8—C9—C10 = 70.8 (3)°. In the crystal, mol­ecules form chains extending along the b-axis direction through C1—H1⋯O1 hydrogen bonds (Table 1[link] and Fig. 2[link]). These chains pack to form zigzag sheets lying parallel to (101), possibly aided by weak C5—H5a⋯π(Cg2) inter­actions [Cg2 is the centroid of the aromatic ring at (−x + [{3\over 2}], y − [{1\over 2}], −z + [{3\over 2}])], with H⋯Cg = 3.84 Å and C—H⋯Cg = 138° (Fig. 3[link]).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C1—H1⋯O1ii 0.93 2.54 3.396 (2) 153
Symmetry code: (ii) x, y+1, z.
[Figure 1]
Figure 1
The title mol­ecule with the atom-labeling scheme and 50% probability ellipsoids. [Symmetry code: (i) −x + 1, y, −z + [{3\over 2}].]
[Figure 2]
Figure 2
Packing viewed towards (101). C—H⋯O hydrogen bonds are depicted by dashed lines.
[Figure 3]
Figure 3
Packing viewed along the b-axis direction.

Synthesis and crystallization

A mixture of quinoxaline-2,3-dione (1.0 g, 6.17 mmol), potassium carbonate (1.7 g, 12.33 mmol), bromo­hexane (1.73 ml, 12.33 mmol) and tetra-n-butyl­ammonium bromide as a catalyst in N,N-di­methyl­formamide (60 ml) was stirred at room temperature for 48 h. After completion of the reaction (monitored by thin-layer chromatography), the solvent was removed under vacuum and the residue was chromatographed on a silica-gel column using hexane and ethyl acetate (80:20 v/v) as eluent. The compound obtained was recrystallzed from ethanol solution to afford the title compound as colourless blocks.

Refinement

Crystal and refinement details are given in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C20H30N2O2
Mr 330.46
Crystal system, space group Monoclinic, C2/c
Temperature (K) 295
a, b, c (Å) 13.357 (3), 9.209 (2), 16.743 (4)
β (°) 113.277 (3)
V3) 1891.9 (7)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.08
Crystal size (mm) 0.28 × 0.25 × 0.18
 
Data collection
Diffractometer Bruker SMART APEX CCD
Absorption correction Multi-scan (SADABS; Bruker, 2016[Bruker (2016). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.72, 0.99
No. of measured, independent and observed [I > 2σ(I)] reflections 8628, 2323, 1475
Rint 0.040
(sin θ/λ)max−1) 0.666
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.062, 0.196, 1.04
No. of reflections 2323
No. of parameters 110
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.26, −0.22
Computer programs: APEX3 (Bruker, 2016[Bruker (2016). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SAINT (Bruker, 2016[Bruker (2016). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), DIAMOND (Brandenburg & Putz, 2012[Brandenburg, K. & Putz, H. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Structural data


Computing details top

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg & Putz, 2012); software used to prepare material for publication: SHELXTL (Bruker, 2016).

1,4-Dihexyl-1,2,3,4-tetrahydroquinoxaline-2,3-dione top
Crystal data top
C20H30N2O2F(000) = 720
Mr = 330.46Dx = 1.160 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 13.357 (3) ÅCell parameters from 2136 reflections
b = 9.209 (2) Åθ = 2.7–27.4°
c = 16.743 (4) ŵ = 0.08 mm1
β = 113.277 (3)°T = 295 K
V = 1891.9 (7) Å3Block, colourless
Z = 40.28 × 0.25 × 0.18 mm
Data collection top
Bruker SMART APEX CCD
diffractometer
2323 independent reflections
Radiation source: fine-focus sealed tube1475 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
Detector resolution: 8.3333 pixels mm-1θmax = 28.3°, θmin = 2.7°
ω scansh = 1717
Absorption correction: multi-scan
(SADABS; Bruker, 2016)
k = 1212
Tmin = 0.72, Tmax = 0.99l = 2122
8628 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.062Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.196H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0925P)2 + 0.3797P]
where P = (Fo2 + 2Fc2)/3
2323 reflections(Δ/σ)max < 0.001
110 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.22 e Å3
Special details top

Experimental. The diffraction data were collected in three sets of 363 frames (0.5° width in ω) at φ = 0, 120 and 240°. A scan time of 60 sec/frame was used.

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. 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 > 2sigma(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. H-atoms attached to carbon were placed in calculated positions (C—H = 0.95 - 0.99 Å). All were included as riding contributions with isotropic displacement parameters 1.2 - 1.5 times those of the attached atoms.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.58538 (12)0.26991 (13)0.72515 (11)0.0825 (5)
N10.58320 (10)0.51512 (13)0.71964 (8)0.0427 (4)
C10.53793 (13)0.90866 (18)0.73135 (12)0.0572 (5)
H10.56240.99600.71770.069*
C20.57667 (12)0.77985 (17)0.71467 (10)0.0500 (4)
H20.62820.78070.69020.060*
C30.54071 (10)0.64763 (15)0.73341 (9)0.0387 (4)
C40.54659 (13)0.38519 (17)0.73476 (11)0.0523 (4)
C50.67419 (13)0.51352 (18)0.69052 (11)0.0485 (4)
H5A0.71500.42410.70990.058*
H5B0.72290.59370.71760.058*
C60.63673 (13)0.52534 (19)0.59270 (11)0.0515 (4)
H6A0.59500.61390.57270.062*
H6B0.58960.44390.56520.062*
C70.73340 (14)0.5263 (2)0.56635 (11)0.0561 (5)
H7A0.78070.60710.59480.067*
H7B0.77470.43750.58660.067*
C80.70034 (17)0.5390 (2)0.46884 (13)0.0676 (6)
H8A0.65970.62830.44880.081*
H8B0.65230.45890.44050.081*
C90.79629 (19)0.5382 (3)0.44171 (14)0.0778 (6)
H9A0.77090.56750.38130.093*
H9B0.84920.60950.47610.093*
C100.8516 (3)0.3937 (3)0.4521 (2)0.1177 (10)
H10A0.79920.32140.42040.177*
H10B0.88320.36790.51260.177*
H10C0.90780.39910.43010.177*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.1072 (12)0.0452 (8)0.1324 (13)0.0121 (7)0.0871 (11)0.0001 (7)
N10.0406 (7)0.0436 (7)0.0549 (8)0.0030 (5)0.0307 (6)0.0019 (5)
C10.0525 (10)0.0403 (9)0.0791 (12)0.0077 (7)0.0264 (8)0.0037 (8)
C20.0438 (9)0.0476 (9)0.0668 (10)0.0059 (7)0.0306 (8)0.0017 (7)
C30.0343 (7)0.0391 (8)0.0479 (8)0.0002 (5)0.0218 (6)0.0002 (6)
C40.0642 (11)0.0406 (8)0.0686 (11)0.0034 (7)0.0438 (9)0.0002 (7)
C50.0396 (8)0.0610 (10)0.0558 (10)0.0072 (7)0.0306 (7)0.0027 (7)
C60.0446 (9)0.0628 (10)0.0552 (10)0.0012 (7)0.0282 (7)0.0001 (7)
C70.0522 (10)0.0712 (11)0.0555 (10)0.0018 (8)0.0328 (8)0.0013 (8)
C80.0656 (12)0.0890 (14)0.0603 (11)0.0026 (10)0.0377 (10)0.0003 (9)
C90.0850 (15)0.0988 (16)0.0699 (12)0.0136 (12)0.0524 (11)0.0046 (10)
C100.140 (2)0.116 (2)0.145 (2)0.0097 (19)0.108 (2)0.0140 (18)
Geometric parameters (Å, º) top
O1—C41.2195 (18)C6—H6A0.9700
N1—C41.3537 (19)C6—H6B0.9700
N1—C31.4027 (17)C7—C81.518 (2)
N1—C51.4777 (17)C7—H7A0.9700
C1—C21.366 (2)C7—H7B0.9700
C1—C1i1.385 (3)C8—C91.520 (3)
C1—H10.9300C8—H8A0.9700
C2—C31.3895 (19)C8—H8B0.9700
C2—H20.9300C9—C101.498 (4)
C3—C3i1.403 (3)C9—H9A0.9700
C4—C4i1.520 (3)C9—H9B0.9700
C5—C61.515 (2)C10—H10A0.9600
C5—H5A0.9700C10—H10B0.9600
C5—H5B0.9700C10—H10C0.9600
C6—C71.521 (2)
C4—N1—C3122.59 (12)H6A—C6—H6B108.0
C4—N1—C5117.25 (12)C8—C7—C6113.14 (15)
C3—N1—C5120.12 (11)C8—C7—H7A109.0
C2—C1—C1i119.73 (9)C6—C7—H7A109.0
C2—C1—H1120.1C8—C7—H7B109.0
C1i—C1—H1120.1C6—C7—H7B109.0
C1—C2—C3121.46 (14)H7A—C7—H7B107.8
C1—C2—H2119.3C7—C8—C9113.57 (17)
C3—C2—H2119.3C7—C8—H8A108.9
C2—C3—N1121.79 (12)C9—C8—H8A108.9
C2—C3—C3i118.72 (8)C7—C8—H8B108.9
N1—C3—C3i119.49 (7)C9—C8—H8B108.9
O1—C4—N1122.75 (15)H8A—C8—H8B107.7
O1—C4—C4i119.42 (9)C10—C9—C8113.86 (19)
N1—C4—C4i117.83 (8)C10—C9—H9A108.8
N1—C5—C6113.11 (13)C8—C9—H9A108.8
N1—C5—H5A109.0C10—C9—H9B108.8
C6—C5—H5A109.0C8—C9—H9B108.8
N1—C5—H5B109.0H9A—C9—H9B107.7
C6—C5—H5B109.0C9—C10—H10A109.5
H5A—C5—H5B107.8C9—C10—H10B109.5
C5—C6—C7111.00 (14)H10A—C10—H10B109.5
C5—C6—H6A109.4C9—C10—H10C109.5
C7—C6—H6A109.4H10A—C10—H10C109.5
C5—C6—H6B109.4H10B—C10—H10C109.5
C7—C6—H6B109.4
C1i—C1—C2—C30.7 (3)C3—N1—C4—C4i1.9 (3)
C1—C2—C3—N1177.46 (15)C5—N1—C4—C4i179.67 (16)
C1—C2—C3—C3i2.9 (3)C4—N1—C5—C696.77 (17)
C4—N1—C3—C2177.72 (14)C3—N1—C5—C685.38 (17)
C5—N1—C3—C24.5 (2)N1—C5—C6—C7178.85 (13)
C4—N1—C3—C3i2.0 (3)C5—C6—C7—C8179.63 (15)
C5—N1—C3—C3i175.77 (15)C6—C7—C8—C9179.30 (16)
C3—N1—C4—O1177.92 (16)C7—C8—C9—C1070.8 (3)
C5—N1—C4—O10.1 (3)
Symmetry code: (i) x+1, y, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···O1ii0.932.543.396 (2)153
Symmetry code: (ii) x, y+1, z.
 

References

First citationBrandenburg, K. & Putz, H. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBruker (2016). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationEl Bourakadi, K., El Bakri, Y., Sebhaoui, J., Rayni, I., Essassi, E. M. & Mague, J. T. (2017a). IUCrData, 2, x170520.  Google Scholar
First citationEl Bourakadi, K., El Bakri, Y., Sebhaoui, J., Rayni, I., Essassi, E. M. & Mague, J. T. (2017b). IUCrData, 2, x170656.  Google Scholar
First citationFerfra, S., Ahabchane, N. H., Mustaphi, N. E., Essassi, E. M., Bellan, J. & Pierrot, M. (2001). Phosphorus Sulfur Silicon, 175, 169–181.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSheldrick, 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.

Journal logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds