3-Allyl-1-{[3-(4-nitro­phen­yl)-4,5-dihydro-1,3-oxazol-5-yl]meth­yl}-1H-anthra[1,2-d]imidazole-2,6,11(3H)-trione

Zahra Afrakssou; Amal Haoudi; Frédéric Capet; Christian Rolando; Lahcen El Ammari

doi:10.1107/S1600536811016606

. 2011 May 7;67(Pt 6):o1363–o1364. doi: 10.1107/S1600536811016606

3-Allyl-1-{[3-(4-nitrophenyl)-4,5-dihydro-1,3-oxazol-5-yl]methyl}-1H-anthra[1,2-d]imidazole-2,6,11(3H)-trione

Zahra Afrakssou ^a,^*, Amal Haoudi ^a, Frédéric Capet ^b, Christian Rolando ^c, Lahcen El Ammari ^d

PMCID: PMC3120525 PMID: 21754757

Abstract

The molecular structure of the title compound, C₂₈H₂₀N₄O₆, consists of three fused six-membered rings (A,B,C) and one five-membered ring (D). The latter is linked to an isoxazole ring (E) via a methylene unit. A 4-nitro-phenyl substituent (F) is attached to the isoxazole. The fused five and six-membered rings (C,D) are almost coplanar with an r.m.s. deviation of 0.0345 Å and make a dihedral angle of 9.40 (8)° with ring A. The isoxazole and 4-nitro-phenyl rings (E,F) are also almost coplanar with the imidazole and the fused adjacent ring (C,D), forming a dihedral angle of 11.4 (6)°. The crystal packing displays intermolecular C—H⋯O hydrogen bonding. An intramolecular C—H⋯O interaction also occurs.

Related literature

For the biological activity of anthraquinone derivatives, see: Agarwal et al. (2000 ▶); Barnard et al. (1995 ▶); Chen et al. (2007 ▶); Haug et al. (2003 ▶); Iizuka et al. (2004 ▶); Koyamaa et al. (2002 ▶); Su et al. (2005 ▶); Wu et al. (2005 ▶); Yen et al. (2000 ▶). For a derivative of the title compound, see: Afrakssou et al. (2010 ▶). For the use of related compounds as synthetic dyes, see: Simi et al. (1995 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₈H₂₀N₄O₆
M _r = 508.48
Monoclinic,
a = 10.0780 (3) Å
b = 22.7094 (6) Å
c = 11.2729 (3) Å
β = 113.809 (1)°
V = 2360.41 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.40 × 0.14 × 0.11 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS, Bruker, 2009) ▶ T _min = 0.704, T _max = 0.745
47772 measured reflections
4828 independent reflections
2998 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.111
S = 1.00
4828 reflections
343 parameters
H-atom parameters constrained
Δρ_max = 0.12 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT-Plus (Bruker, 2009 ▶); data reduction: SAINT-Plus; 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 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811016606/im2283sup1.cif

e-67-o1363-sup1.cif^{(21.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811016606/im2283Isup2.hkl

e-67-o1363-Isup2.hkl^{(231.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811016606/im2283Isup3.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
C7—H7⋯O1ⁱ	0.93	2.60	3.516 (2)	169
C18—H18B⋯O2ⁱⁱ	0.97	2.37	3.333 (2)	170
C26—H26B⋯O1ⁱ	0.97	2.55	3.379 (3)	144
C16—H16A⋯O2	0.97	2.10	2.902 (2)	141

Open in a new tab

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

supplementary crystallographic information

Comment

Recently, a number of pharmacological tests revealed that anthraquinone derivatives present various biological activities including antifungal (Agarwal et al., 2000), antimicrobial (Wu et al., 2005), anticancer (Koyamaa et al., 2002; Su et al., 2005; Chen et al., 2007), antioxidant (Yen et al., 2000; Iizuka et al., 2004), and antihuman cytomegalovirus activity (Barnard et al., 1995).

Aminoanthraquinone derivatives are a class of compounds largely used as phytotherapeutic drugs (laxatives, sedatives and antikidney and antibladder stones) and colouring agents (in the food, cosmetics and textile) (Simi et al., 1995). Anthraquinone derivatives have also been utilized for the activation of human telomerase reverse transcriptase expression (Haug et al., 2003), and they act as telomerase inhibitors or activators.

Due to their importance, in a previous study we have synthesized 1,3-diallyl-1H-anthra[1,2-d]imidazole-2,6,11(3H)-trione (Afrakssou et al., 2010). Here we have focused on the reactivity of the exocyclic C=C bond of the allyl substituents towards nitriloxides. The latter are produced as intermediates in the dehydrohalogenation of 4-nitrobenzaldoxime by a solution of sodium hypochlorite. The oxime then reacts with 1,3-diallyl-1H-anthra[1,2-d] imidazole-2,6,11(3H)-trione in a biphasic medium (water-chloroform) at 0°C during 4 h to a unique cycloadduct 3-allyl-1-[3 -(4-nitro-phenyl)-4,5-dihydro-isoxazole-5-ylmethyl] -1,3-dihydro-anthra [1,2 d] imidazole-2,6,11-trione (Scheme 1). Due to this reaction sequence a racemate of the title compound which shows a stereogenic center at C(17) is formed.

Fig.1 shows the molecular plot of the crystal structure of the title compound. The isoxazole (E) adopts an envelope conformation on C(17) as indicated by the Cremer & Pople (1975) puckering parameters Q2 = 0.2117 (19) Å and φ2 = 141.6 (5)°. Moreover, ring (B) has a twisted conformation, with puckering parameters Q = 0.1480 (19) Å, θ = 114.6 (8) ° and φ = 139.7 (8) °, whereas all other rings are planar. The dihedral angles between fused five and six-membered rings (C,D) and the isoxazole ring (E) is 11.4 (6)°. The torsion angle between C27—C26—N2—C1 is 87.42 (0.22)°. In the crystal, adjacent molecules are linked by intermolecular C–H···O hydrogen bonding as shown in Fig. 2 and Table 1.

Experimental

To a solution of 1,3-diallyl-1H-anthra[1,2-d] imidazole-2,6,11(3H)-trione (0.3 g, 0.87 mmol) and 4-nitrobenzaldoxime (0.36 g, 2.17 mmol) in chloroform (16 ml) was added dropwise a 24% sodium hypochlorite solution (8 ml) at 273 K. Stirring was continued for 4 h. The organic layer was dried over Na₂SO₄ and the solvent was evaporated under reduced pressure. The residue was then purified by column chromatography on silica gel using a mixture of hexane/ethyl acetate (1/1) as eluent. The title compound is formed as a racemate (Yield: 35%). Orange crystals are isolated after the solvent was allowed to evaporate.