Benzyl N-{2-[5-(4-chloro­phen­yl)-1,2,4-oxadiazol-3-yl]propan-2-yl}carbamate

Hoong-Kun Fun; V Sumangala; G K Nagaraja; Boja Poojary; Suchada Chantrapromma

doi:10.1107/S1600536811001504

. 2011 Jan 15;67(Pt 2):o420–o421. doi: 10.1107/S1600536811001504

Benzyl N-{2-[5-(4-chlorophenyl)-1,2,4-oxadiazol-3-yl]propan-2-yl}carbamate

Hoong-Kun Fun ^a,^*,^‡, V Sumangala ^b, G K Nagaraja ^b, Boja Poojary ^b, Suchada Chantrapromma ^c,^§

PMCID: PMC3051527 PMID: 21523090

Abstract

In the title 1,2,4-oxadiazole derivative, C₁₉H₁₈ClN₃O₃, the 1,2,4-oxadiazole ring makes dihedral angles of 12.83 (8) and 4.89 (8)°, respectively, with the benzyl and 4-chlorophenyl rings, while the dihedral angle between the benzyl and 4-chlorophenyl rings is 11.53 (7)°. In the crystal, molecules are linked by N—H⋯N hydrogen bonds into helical chains along the b axis. A weak C—H⋯π interaction is also present.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For background to and applications of 1,2,4-oxadiazole derivatives, see: Chen et al. (1994 ▶); Chimirri et al. (1996 ▶); Clitherow et al. (1996 ▶); Nicolaides et al. (1998 ▶); Saunders et al. (1990 ▶); Showell et al. (1991 ▶); Swain et al. (1991 ▶); Tully et al. (1991 ▶); Watjen et al. (1989 ▶). For a related structure, see: Fun et al. (2011 ▶).

Experimental

Crystal data

C₁₉H₁₈ClN₃O₃
M _r = 371.81
Orthorhombic,
a = 7.7501 (1) Å
b = 11.0052 (2) Å
c = 20.9834 (3) Å
V = 1789.70 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 297 K
0.41 × 0.35 × 0.21 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.908, T _max = 0.951
15995 measured reflections
4556 independent reflections
3620 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.087
S = 1.02
4556 reflections
241 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.21 e Å⁻³
Absolute structure: Flack (1983 ▶), 1950 Friedel pairs
Flack parameter: 0.01 (6)

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); 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/S1600536811001504/is2659sup1.cif

e-67-0o420-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811001504/is2659Isup2.hkl

e-67-0o420-Isup2.hkl^{(223.2KB, hkl)}

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

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

Cg1 is the centroid of the C12–C17 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H1N3⋯N2ⁱ	0.840 (16)	2.428 (15)	3.2492 (18)	165.7 (14)
C16—H16A⋯Cg1ⁱⁱ	0.93	2.91	3.6700 (18)	140

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

Acknowledgments

VS, GKN and BP thank Mangalore University for a research grant. SC thanks the Prince of Songkla University for generous support. The authors thank Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

The 1,2,4-oxadiazole ring occurs frequently in biologically active synthetic compounds and 1,2,4-oxadiazole derivatives are suggested as potential agonists for cortical muscarinic (Saunders et al., 1990; Showell et al., 1991), benzodiazepine (Watjen et al., 1989; Tully et al., 1991) and 5-HT1D (5-hydroxytryptamine) as receptors (Chen et al., 1994) as well as antagonists for 5-HT3 (Swain et al., 1991) or histamine H3 receptors (Clitherow et al., 1996). They also demonstrate anti-inflammatory (Nicolaides et al., 1998) and antitumor activities (Chimirri et al., 1996). These interesting and important properties of 1,2,4-oxadiazole derivatives lead us to synthesize the title compound (I) and its crystal structure was reported.

In the molecule of (I), (Fig. 1), the 1,2,4-oxadiazole ring is nearly co-planar with the 4-chlorophenyl with a dihedral angle between the two rings being 4.89 (8)°, whereas it is inclined to the benzyl (C11–C17) unit with a dihedral angle of 12.48 (9)°. The dihedral angle between the benzyl group and the phenyl (C1–C6) ring is 11.53 (7)°. The oxycarbonylamino unit (atoms C10, N3, O2 and O3) is planar with an r.m.s. 0.0009 (1) Å. This unit makes dihedral angles of 79.99 (9), 89.15 (9) and 89.64 (9)°, respectively, with the benzyl, 1,2,4-oxadiazole and 4-chlorophenyl rings. The bond distances are of normal values (Allen et al., 1987) and are comparable to the related structure (Fun et al., 2011).

In the crystal packing (Fig. 2), the molecules are linked by by N—H···N hydrogen bonds (Table 1) into helical chains along the b axis. The crystal is stabilized by N—H···O hydrogen bonds and weak C—H···π interactions (Table 1).

Experimental

The title compound was synthesized by taking benzyl [(2E)-2-amino-2-(hydroxyimino)-1,1-dimethylethyl]carbamate (0.1 mole) in 5 mol volume of pyridine and treated with 0.1 mole of 4-chlorobenzoylchloride. The reaction mixture is heated to reflux for 3–4 hrs. After the reaction is completed, the excess pyridine is distilled out under low pressure and the resultant quenched onto ice water. The solid thus formed is filtered and washed with water. The sample is dried and recrystallized in ethanol yielding 95% product. Colorless plate-shaped single crystals of the title compound suitable for x-ray structure determination were recrystalized from ethanol by the slow evaporation of the solvent at room temperature after several days (m.p. 405–409 K).