1-Isopropyl-4,7-dimethyl-2,8-dinitro­naphthalene

Mouna Chakkar; Najia Oughris; Ahmed Benharref; Jean-Claude Daran; Moha Berraho

doi:10.1107/S1600536812021514

. 2012 May 26;68(Pt 6):o1893. doi: 10.1107/S1600536812021514

1-Isopropyl-4,7-dimethyl-2,8-dinitronaphthalene

Mouna Chakkar ^a,^*, Najia Oughris ^a, Ahmed Benharref ^a, Jean-Claude Daran ^b, Moha Berraho ^a

PMCID: PMC3379451 PMID: 22719649

Abstract

The title compound, C₁₅H₁₆N₂O₄, was synthesized from a mixture of α-himachalene (2-methylene-6,6,9-trimethylbicyclo[5.4.O^1,7]undec-8-ene) and β-himachalene (2,6,6,9-tetramethylbicyclo[5.4.0^1,7]undeca-1,8-diene) which were isolated from an oil of the Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent molecules. In each of the two molecules, two O atoms of one nitro group are disordered over two sets of sites with site-occupancy factors of 0.636 (5):0.364 (5) and 0.832 (5):0.168 (5). The crystal structure features weak C—H⋯O hydrogen bonds.

Related literature

For the isolation of α-himachalene and β-himachalene, see: Joseph & Dev (1968 ▶); Plattier & Teisseire (1974 ▶); Daunis et al. (1981 ▶). For the reactivity of this sesquiterpene, see: Lassaba et al. (1998 ▶); Chekroun et al. (2000 ▶); El Jamili et al. (2002 ▶); Sbai et al. (2002 ▶); Dakir et al. (2004 ▶). For its biological activity, see: Daoubi et al. (2004 ▶).

Experimental

Crystal data

C₁₅H₁₆N₂O₄
M _r = 288.30
Triclinic,
a = 11.7784 (7) Å
b = 11.9072 (9) Å
c = 12.4494 (10) Å
α = 107.928 (7)°
β = 112.834 (7)°
γ = 104.536 (6)°
V = 1387.6 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 180 K
0.49 × 0.22 × 0.14 mm

Data collection

Agilent Xcalibur Sapphire1 (long-nozzle) diffractometer
25504 measured reflections
4881 independent reflections
4084 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.152
S = 1.08
4881 reflections
425 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812021514/bt5912sup1.cif

e-68-o1893-sup1.cif^{(35KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812021514/bt5912Isup2.hkl

e-68-o1893-Isup2.hkl^{(234.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812021514/bt5912Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11B—H11C⋯O82ⁱ	0.98	2.42	3.243 (6)	142
C11A—H11F⋯O84Aⁱⁱ	0.98	2.43	3.240 (5)	139

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Symmetry codes: (i) Inline graphic ; (ii) .

supplementary crystallographic information

Comment

The bicyclic sesquiterpenes α- and β-himachalene are the main constituents of the essential oil of the Atlas cedar (Cedrus atlantica) (Joseph & Dev, 1968; Plattier & Teisseire, 1974). The reactivity of these sesquiterpenes and its derivatives has been studied extensively by our team in order to prepare new products having biological proprieties (Lassaba et al., 1998; Chekroun et al., 2000; El Jamili et al., 2002; Sbai et al., 2002; Dakir et al., 2004). Indeed, these compounds were tested, using the food poisoning technique, for their potential antifungal activity against the phytopathogen Botrytis cinerea (Daoubi et al., 2004). The catalytic dehydrogenation of the mixture of α- and β-himachalene by 5% of palladium on carbon(10%) gives, with good yield, the aryl-himachalene (Daunis et al., 1981). Treatement of the latter by a mixture of nitric acid and sulfuric acid, gives the title compound with a yield of 20%. The structure of this new product was confirmed by its crystal structure. The molecular structure of (I) is shown in Fig. 1. The asymmetric unit contains two molecules of 1-isopropyl-4,7-dimethyl-2,8-dinitro-naphthalene. The naphthalene ring systems are approximately planar with r.s.d.deviations of 0.087 (2) and 0.090 (2) A°. The bond lengths and angles are within normal ranges in both molecules. In the crystal structure, the two molecules are not parallel but have a dihedral angle of 1.54 (7)°. The crystal structure is stabilized by intermolecular C–H···O hydrogen bonds, which link the molecules into chains parallel to the c axis (Fig. 2, Table 1).

Experimental

In a reactor of 250 ml equipped with a magnetic stirrer and a dropping funnel, we introduct 60 ml of dichloromethane, 3 ml of nitric acid and 5 ml of concentrated sulfuric acid. After cooling, added dropwise through the dropping funnel 6 g (30 mmol) of aryl-himachalene dissolved in 30 ml of dichloromethane. The reaction mixture was stirred for 4 h, then added 50 ml of water ice and extracted with dichloromethane. The organic layers were combined, washed five times with 4O ml with water and dried over sodium sulfate and then concentrated under vacuum. The residue was subjected to chromatography on a column of silica gel with hexane-ethyl acetate (98/2) as eluent, to obtain 1.7 g (6 mmol) of the title compound which was recrystallized in ethyl acetate.