N′-[(E)-4-Chloro­benzyl­idene]-2-(4-isobutyl­phen­yl)propanohydrazide

Hoong-Kun Fun; Chin Sing Yeap; K V Sujith; B Kalluraya

doi:10.1107/S1600536809015906

. 2009 May 7;65(Pt 6):o1196–o1197. doi: 10.1107/S1600536809015906

N′-[(E)-4-Chlorobenzylidene]-2-(4-isobutylphenyl)propanohydrazide

Hoong-Kun Fun ^a,^*,^‡, Chin Sing Yeap ^a,^§, K V Sujith ^b, B Kalluraya ^b

PMCID: PMC2969596 PMID: 21583068

Abstract

The asymmetric unit of title compound, C₂₀H₂₃ClN₂O, consists of two crystallographically independent molecules (A and B) in which the orientations of the 4-isobutylphenyl units are different. The isobutyl group of molecule B is disordered over two positions with occupancies of 0.850 (5) and 0.150 (5). The dihedral angle between the two benzene rings is 88.70 (9)° in molecule A and 89.38 (9)° in molecule B. The independent molecules are linked together into chains along [100] by N—H⋯O and C—H⋯O hydrogen bonds, and by C—H⋯π interactions. In the chain, N—H⋯O and C—H⋯O hydrogen bonds generate R ₂ ¹(6) ring motifs. In addition, C—H⋯N hydrogen bonds are observed. The presence of pseudosymmetry in the structure suggests the higher symmetry space group Pbca but attempts to refine the structure in this space group resulted in high R (0.119) and wR (0.296) values.

Related literature

For general background and biological applications of hydrazone compounds, see: Kawail et al. (2005 ▶); Klasser & Epstein, (2005 ▶); Sridhar & Perumal (2003 ▶); Bedia et al. (2006 ▶); Rollas et al. (2002 ▶); Terzioglu & Gürsoy, (2003 ▶). For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For the crystal structure of the bromo analogue, see: Fun et al. (2009 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₀H₂₃ClN₂O
M _r = 342.85
Orthorhombic,
a = 9.1405 (1) Å
b = 11.9260 (2) Å
c = 33.3487 (5) Å
V = 3635.33 (9) Å³
Z = 8
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 100 K
0.56 × 0.18 × 0.15 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.887, T _max = 0.967
26510 measured reflections
10652 independent reflections
8888 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.118
S = 1.02
10652 reflections
453 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.26 e Å⁻³
Absolute structure: Flack (1983 ▶), 4712 Friedel pairs
Flack parameter: 0.10 (5)

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/S1600536809015906/ci2793sup1.cif

e-65-o1196-sup1.cif^{(32.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809015906/ci2793Isup2.hkl

e-65-o1196-Isup2.hkl^{(520.9KB, hkl)}

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

Table 1. Selected torsion angles (°).

C20A—C9A—C10A—C11A	159.65 (17)
C20A—C9A—C10A—C15A	−21.5 (3)
C20B—C9B—C10B—C11B	−140.01 (18)
C20B—C9B—C10B—C15B	43.2 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H1NA⋯O1B	0.86	2.02	2.821 (2)	155
C7A—H7AA⋯O1B	0.93	2.54	3.313 (2)	140
C12A—H12A⋯Cg1	0.93	2.75	3.632 (2)	159
N2B—H1NB⋯O1Aⁱ	0.86	2.02	2.832 (2)	157
C7B—H7BA⋯O1Aⁱ	0.93	2.47	3.256 (2)	143
C12B—H12B⋯Cg2ⁱ	0.93	2.65	3.462 (2)	146
C20A—H20B⋯N1Bⁱⁱ	0.96	2.57	3.504 (3)	164

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 and Cg2 are the centroids of the C1B–C6B and C1A–C6A rings, respectively.

Acknowledgments

HKF thanks Universiti Sains Malaysia for the Research University Golden Goose Grant (No. 1001/PFIZIK/811012). CSY thanks the Malaysian Government and Universiti Sains Malaysia for the award of a post of research officer under the Science Fund (grant No. 305/PFIZIK/613312).

supplementary crystallographic information

Comment

Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are widely used in the treatment of pain and inflammation (Kawail et al., 2005; Klasser & Epstein, 2005). Aryl hydrazones are important building blocks for the synthesis of a variety of heterocyclic compounds such as pyrazolines and pyrazoles (Sridhar & Perumal, 2003). Aryl hydrazones have been most conveniently synthesized by the reaction of aryl hydrazines with carbonyl compounds. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Hydrazones have been demonstrated to possess antimicrobial, anticonvulsant, analgesic, antiinflammatory, antiplatelet, antitubercular, anticancer and antitumoral activities (Bedia et al., 2006; Rollas et al., 2002; Terzioglu & Gürsoy, 2003). These observations have been the guide for the development of new hydrazones that possess varied biological activities. Prompted by these observations, the title compoud was synthesized and its crystal structure is reported here.

The asymmetric unit of title compound (Fig. 1), consists of two crystallographically independent molecules, A and B, in which the orientations of the 4-isobutylphenyl units are different (Table 1). Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable with those in the bromo analogue (Fun et al., 2009). The dihedral angle between the two benzene rings is 88.70 (9)° in molecule A and 89.38 (9)° in molecule B. The molecule A is linked to the molecule B by intermolecular C7A—H7AA···O1B and N2A—H1NA···O1B hydrogen bonds, generating an R₂¹(6) ring motif (Bernstein et al., 1995) and by an C—H···π interaction.

In the crystal structure, the independent molecules are linked together into chains along the [100] (Fig. 2) by N—H···O and C—H···O hydrogen bonds, and C—H···π interactions (Table 2). In addition, C—H···N hydrogen bonds are observed.

Experimental

A mixture of 2-[4-(2-methylpropyl)phenyl]propanehydrazide (0.01 mol) and 4-chlorobenzaldehyde (0.01 mol) in ethanol (30 ml) along with 3 drops of concentrated sulphuric acid was refluxed for 1 h. Excess ethanol was removed from the reaction mixture under reduced pressure. The solid product obtained was filtered, washed with ethanol and dried. Single crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution (yield 87%; m.p.430-433 K).