2,5-Bis(4-meth­oxy­phen­yl)-1,3,4-oxadiazole

Hoong-Kun Fun; Jia Hao Goh; Nithinchandra; B Kalluraya

doi:10.1107/S1600536810044405

. 2010 Nov 6;66(Pt 12):o3072. doi: 10.1107/S1600536810044405

2,5-Bis(4-methoxyphenyl)-1,3,4-oxadiazole

Hoong-Kun Fun ^a,^*,^‡, Jia Hao Goh ^a,^§, Nithinchandra ^b, B Kalluraya ^b

PMCID: PMC3011497 PMID: 21589381

Abstract

In the title compound, C₁₆H₁₄N₂O₃, the essentially planar 1,3,4-oxadiazole ring [maximum deviation = 0.0021 (11) Å] is inclined at dihedral angles of 8.06 (6) and 11.21 (6)° with respect to the two benzene rings; the dihedral angle between the latter rings is 11.66 (5)°. In the crystal, short intermolecular C⋯O interactions [2.9968 (15) Å] connect adjacent molecules into chains propagating in [203]. The crystal structure is further stabilized by weak intermolecular C—H⋯π interactions.

Related literature

For general background to and applications of the title compound, see: Andersen et al. (1994 ▶); Clitherow et al. (1996 ▶); Hegde et al. (2008 ▶); Rai et al. (2008 ▶); Showell et al. (1991 ▶). For closely related 2,5-diphenyl-1,3,4-oxadiazole structures, see: Reck et al. (2003a ▶,b ▶); Franco et al. (2003 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₆H₁₄N₂O₃
M _r = 282.29
Monoclinic,
a = 10.7525 (2) Å
b = 11.8973 (2) Å
c = 11.6340 (2) Å
β = 115.434 (1)°
V = 1344.04 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.53 × 0.49 × 0.09 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.950, T _max = 0.992
17061 measured reflections
4744 independent reflections
3744 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.137
S = 1.03
4744 reflections
246 parameters
All H-atom parameters refined
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810044405/hb5714sup1.cif

e-66-o3072-sup1.cif^{(19KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810044405/hb5714Isup2.hkl

e-66-o3072-Isup2.hkl^{(232.4KB, hkl)}

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

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

Cg1 and Cg2 are the centroids of C9–C14 and C1–C6 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15A⋯Cg1ⁱ	1.031 (14)	2.563 (16)	3.4903 (14)	149.4 (10)
C15—H15B⋯Cg2ⁱⁱ	0.992 (14)	2.994 (16)	3.8804 (14)	149.4 (11)

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

Acknowledgments

The authors thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160).

supplementary crystallographic information

Comment

Heterocyclic compounds are becoming increasingly important in recent years due to their pharmacological activities (Rai et al., 2008). Nitrogen- and oxygen-containing five/six-membered heterocyclic compounds are of enormous significance in the field of medicinal chemistry (Hegde et al., 2008). Oxadiazoles play a very vital role in the preparation of various biologically active drugs with anti-inflammatory (Andersen et al., 1994) and anti-cancer (Showell et al., 1991) activities. The results of biological studies showed that oxadiazole derivatives also possess significant anti-inflammatory, analgesic and minimum ulcerogenic and lipid per-oxidation (Clitherow et al., 1996) properties.

In the title oxadiazole compound (Fig. 1), the 1,3,4-oxadiazole ring (C7/C8/N1/N2/O1) is essentially planar, with a maximum deviation of -0.0021 (11) at atom N1. The C1-C6 and C9-C14 phenyl rings are inclined at dihedral angles of 11.21 (6) and 8.06 (6)°, respectively, with the 1,3,4-oxadiazole ring. The geometric parameters agree well with those observed in closely related 2,5-diphenyl-1,3,4-oxadiazole structures (Reck et al., 2003a,b; Franco et al., 2003).

In the crystal, no significant intermolecular hydrogen bond is observed. The interesting feature of the crystal structure is the intermolecular short C15···O3 interactions [2.9968 (15) Å, symmetry code: x+1, -y+1/2, z+3/2], which is significantly shorter than the sum of the Van der Waals radii of the relevant atoms (3.22 Å), interconnecting adjacent molecules into one-dimensional chains propagating along the [203] direction (Fig. 2). Further stabilization of the crystal structure is provided by weak intermolecular C15—H15A···Cg1 and C15—H15B···Cg2 interactions (Table 1) where Cg1 and Cg2 are the centroids of C9-C14 and C1-C6 phenyl rings, respectively.

Experimental

An equimolar mixture of 4-methoxybenzoic acid (0.01 mol) and 4-methoxybenzhydrazide was dissolved in POCl₃ (25–30 ml) by gentle warming. The solution is refluxed for about 12 h. Excess of POCl₃ is distilled off, and then the reaction mixture is poured into crushed ice. The separated solid was filtered, washed with water and dried. It was then recrystallized from ethanol. Yellow blocks of (I) were obtained from ethanol by slow evaporation.