Crystal structure of 2-(adamantan-1-yl)-5-(4-bromo­phen­yl)-1,3,4-oxa­diazole

Nourah Z Alzoman; Ali A El-Emam; Hazem A Ghabbour; C S Chidan Kumar; Hoong-Kun Fun

doi:10.1107/S1600536814023861

. 2014 Nov 5;70(Pt 12):o1231–o1232. doi: 10.1107/S1600536814023861

Crystal structure of 2-(adamantan-1-yl)-5-(4-bromophenyl)-1,3,4-oxadiazole

Nourah Z Alzoman ^a, Ali A El-Emam ^a,^b,^*, Hazem A Ghabbour ^a, C S Chidan Kumar ^c,^d,^‡, Hoong-Kun Fun ^a,^c,^*,^§

PMCID: PMC4257436 PMID: 25553016

Abstract

In the title molecule, C₁₈H₁₉BrN₂O, the benzene ring is inclined to the oxadiazole ring by 10.44 (8)°. In the crystal, C—H⋯π interactions link the molecules in a head-to-tail fashion, forming chains extending along the c-axis direction. The chains are further connected by π–π stacking interactions, with centroid–centroid distances of 3.6385 (7) Å, forming layers parallel to the bc plane.

Keywords: crystal structure; adamntane derivative; 1,3,4-oxadiazole; C—H⋯π hydrogen bonds; π–π interactions

Related literature

For the biological activity of adamantane derivatives, see: Al-Abdullah et al. (2014 ▶); Vernier et al. (1969 ▶); El-Emam et al. (2013 ▶); Kadi et al. (2010 ▶); Balzarini et al. (2009 ▶). For the biological activity of adamantyl-1,3,4- oxadiazole derivatives, see: Al-Deeb et al. (2006 ▶); El-Emam et al. (2004 ▶); Kadi et al. (2007 ▶). For related adamantyl 1,3,4-oxadiazole structures, see: El-Emam et al. (2012 ▶); Al-Omary et al. (2014 ▶). For related 2,5-disubstituted 1,3,4-oxadiazole structures, see: Cordes et al. (2011 ▶); Franco et al. (2003 ▶). For the synthesis of the title compound, see: Kadi et al. (2007 ▶). graphic file with name e-70-o1231-scheme1.jpg

Experimental

Crystal data

C₁₈H₁₉BrN₂O
M _r = 359.26
Monoclinic,
a = 13.2571 (5) Å
b = 6.4753 (3) Å
c = 19.6761 (7) Å
β = 114.924 (2)°
V = 1531.76 (11) Å³
Z = 4
Mo Kα radiation
μ = 2.69 mm⁻¹
T = 293 K
0.28 × 0.22 × 0.10 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.520, T _max = 0.779
39946 measured reflections
4678 independent reflections
3996 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.069
S = 1.06
4678 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814023861/rz5137sup1.cif

e-70-o1231-sup1.cif^{(27.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814023861/rz5137Isup2.hkl

e-70-o1231-Isup2.hkl^{(229.2KB, hkl)}

Click here for additional data file.^{(6.3KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814023861/rz5137Isup3.cml

Click here for additional data file.^{(1MB, tif)}

. DOI: 10.1107/S1600536814023861/rz5137fig1.tif

The molecular structure of the title compound with 50% probability displacement ellipsoids.

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S1600536814023861/rz5137fig2.tif

Crystal packing of the title compound, showing the C–H⋯π interactions as dashed lines. Other H-atoms are omitted for clarity.

CCDC reference: 1031604

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

Cg1 is the centroid of the C1C6 ring.

DHA	DH	HA	D A	DHA
C18H18B Cg1ⁱ	0.97	2.74	3.6709(19)	162

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

The financial support of the Deanship of Scientific Research and the Research Center for Female Scientific and Medical Colleges, King Saud University is greatly appreciated. CSCK thanks Universiti Sains Malaysia (USM) for a postdoctoral research fellowship.

supplementary crystallographic information

S1. Comment

Adamantane derivatives have long been known for their diverse biological activities including antiviral activity against the influenza (Vernier et al., 1969) and HIV viruses (El-Emam et al., 2004; Balzarini et al., 2009). In addition, Adamantyl 1,3,4-oxadiazole derivative were reported to exhibit marked antibacterial and anti-inflammatory activities (Kadi et al., 2007, 2010). In continuation to our interest in the chemical and structural properties of adamantane derivatives (El-Emam et al., 2012; Al-Omary et al., 2014) the title compound (I) was prepared as potential bioactive agent.

In the title compound (Fig. 1), the benzene (C1–C6) ring is inclined relative to the oxadiazole (O1/N1/N2/C7/C8) ring by a dihedral angle of 10.44 (8)%. Bond lengths (Allen et al., 1987) and angles in the title compound are within normal ranges and are comparable with those reported earlier for the structure of related compounds (Cordes et al., 2011; Franco et al., 2003). In the crystal structure, the molecules are connected into head-to-tail fashion to form chains extending along the c axis via C–H···π interactions (Table 1, Fig. 2) involving the centroid of the C1–C6 benzene ring (Cg1). In addition, π–π interactions (Cg1··· Cg1ⁱ = 3.6385 (7) Å; symmetry code: (i) -x, -y, 1-z) link the chains into layers parallel to the bc plane.

S2. Experimental

The title compound was prepared following our previously described method (Kadi et al., 2007). A mixture of the 4-bromobenzoic acid hydrazide (2.15 g, 0.01 mol), 1-adamantane carboxylic acid (1.8 g, 0.01 mol) and phosphorus oxychloride (8 ml) was heated under reflux for 1 h. On cooling, crushed ice (50 g) was added cautiously and the mixture was stirred for 30 min. The separated crude product was filtered, washed with water, then with a saturated sodium hydrogen carbonate solution and finally with water, dried and crystallized from EtOH/CHCl₃ (1:1 v/v) to yield 3.16 g (88%) of the title compound (C₁₈H₁₉BrN₂O) as colorless crystals. M. p.: 188–190 °C.

¹H NMR (CDCl₃): δ 1.81 (s, 6H, Adamantane-H), 2.15 (s, 9H, Adamantane-H), 7.64 (d, 2H, Ar—H, J = 8.1 Hz), 7.92 (d, 2H, Ar—H, J = 8.1 Hz). 13 C NMR: δ 27.74, 34.45, 36.29, 39.96 (Adamantane-C), 123.26, 125.99, 128.23, 132.28 (Ar—C), 163.56 (Oxadiazole C-5), 172.85 (Oxadiazole C-2).