Diethyl 1,4-bis­(4-nitro­phen­yl)-1,4-dihydro-1,2,4,5-tetra­zine-3,6-dicarboxyl­ate

Abdesselam Baouid; Aicha Boudina; El Hassane Soumhi

doi:10.1107/S1600536810002217

. 2010 Jan 23;66(Pt 2):o430. doi: 10.1107/S1600536810002217

Diethyl 1,4-bis(4-nitrophenyl)-1,4-dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate

Abdesselam Baouid ^a, Aicha Boudina ^a, El Hassane Soumhi ^b,^*

PMCID: PMC2979708 PMID: 21579845

Abstract

The complete molecule of the title compound, C₂₀H₁₈N₆O₈, is generated by a crystallographic twofold axis. The dihedral angle between the nitrobenzene rings is 43.5 (2)°. The central six-membered ring exhibits a boat conformation. In the crystal structure, weak intermolecular C—H⋯O interactions are observed.

Related literature

For related literature on diazepine and triazepine derivatives, see: Barltrop et al. (1959 ▶); Boudina et al. (2006 ▶); El Hazazi et al. (2003 ▶); Huisgen & Koch (1955 ▶); Nabih et al. (2003 ▶); Sharp & Hamilton (1946 ▶). For related structures, see: Chiaroni et al. (1995 ▶); El Hazazi et al. (2000 ▶).

Experimental

Crystal data

C₂₀H₁₈N₆O₈
M _r = 470.40
Monoclinic,
a = 20.739 (4) Å
b = 7.487 (2) Å
c = 14.587 (3) Å
β = 104.00 (2)°
V = 2197.7 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 300 K
0.30 × 0.15 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
3158 measured reflections
2389 independent reflections
1352 reflections with I > 2σ(I)
R _int = 0.022
2 standard reflections every 60 min intensity decay: 1.0%

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.173
S = 1.04
2389 reflections
155 parameters
All H-atom parameters refined
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810002217/is2514sup1.cif

e-66-0o430-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810002217/is2514Isup2.hkl

e-66-0o430-Isup2.hkl^{(115.1KB, hkl)}

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
C6—H4⋯O2ⁱ	0.93	2.57	3.400 (4)	149
C9—H6⋯O1ⁱⁱ	0.97	2.60	3.294 (4)	129

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

supplementary crystallographic information

Comment

In order to prepare a new heterocyclic systems, our research team have been interested in the 1,3-dipolar cycloaddition reaction of nitrile oxides and nitrilimines toward diazepines, benzodiazepines, triazepines and benzotriazepines (El Hazazi et al., 2003; Nabih et al., 2003; Boudina et al., 2006). In this context, we directed our axe of research to examine reactivity of adducts-obtained from the 1,5-benzodiazepine (Barltrop et al., 1959) via 1,3-dipolar cycloaddition reaction of nitrilimines- with N-paranitrophenylnitrilimine (Sharp & Hamilton, 1946; Huisgen & Koch, 1955). This reaction provided to bicycloadduct and a new heterocycle (A). The new heterocycle (A) resulted from precursor ethyl paranitrophenylhydrazono-α-bromoglyoxylate by the action of triethylamine in dichloromethane at room temperature (Fig. 1).

The structure of product (A) was determined on the basis of NMR spectral data (1H and 13 C) and studied by single-crystal X-ray diffraction (Fig. 2). The asymmetric unit consists of one independent [C₁₀H₉N₃O₄] group that form one half of a molecule compound. The main geometric features of this group are in good agreement with those observed in similar compounds (Chiaroni et al., 1995; El Hazazi et al., 2000). The molecule of nominal compound is localized around a twofold rotation axis and exhibit a boat conformation in which N2 and N2a show the maximum deviation (0.3213 Å) from N3/N2/C7/N3ⁱ/N2ⁱ/C7ⁱ plane [symmetry code: (i) -x + 1, y, -z + 1/2].

Experimental

Triethylamine (0.8 mmol) in dichloromethane (2 ml) was added at room temperature to a stirred solution of ethyl paranitrophenylhydrazono-α-bromoglyoxylate (0.65 mmol) in dichloromethane (20 ml). The mixture was stirred at room temperature, washed with water and the aqueous phase was then extracted with ether (3×20 ml). The organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure and recrystallized from ethanol to afford the reaction product (A) (m.p. = 219–220 °C).