2-Amino-6-(2,4-dichloro­phen­yl)-4-oxo-3,5-diphenyl­cyclo­hex-2-enecarbonitrile

A Jahubar Ali; S Athimoolam; S Asath Bahadur; V P Alex Raja

doi:10.1107/S1600536810035567

. 2010 Sep 18;66(Pt 10):o2593. doi: 10.1107/S1600536810035567

2-Amino-6-(2,4-dichlorophenyl)-4-oxo-3,5-diphenylcyclohex-2-enecarbonitrile

A Jahubar Ali ^a, S Athimoolam ^b, S Asath Bahadur ^c,^*, V P Alex Raja ^d

PMCID: PMC2983276 PMID: 21587572

Abstract

In the title compound, C₂₅H₁₈Cl₂N₂O, the cyclohexene ring has a sofa conformation. All the substituents in the cyclohexene ring, except the cyano group (which is axial) occupy equatorial positions. The crystal structure is stabilized through N—H⋯O hydrogen bonds, forming a chain extending along the b axis and through C—H⋯N and C—H⋯Cl interactions. It is remarkable that only one of the amino H atoms is involved in hydrogen bonding.

Related literature

For the synthesis of the title compound, see: Rodriguez & Dulcere (1993 ▶).

Experimental

Crystal data

C₂₅H₁₈Cl₂N₂O
M _r = 433.31
Monoclinic,
a = 10.8650 (9) Å
b = 14.0010 (3) Å
c = 14.3021 (6) Å
β = 94.697 (10)°
V = 2168.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 293 K
0.21 × 0.18 × 0.12 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
18613 measured reflections
3269 independent reflections
2457 reflections with I > 2σ(I)
R _int = 0.041
θ_max = 23.7°

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.127
S = 1.07
3269 reflections
271 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL/PC (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL/PC; molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXTL/PC.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810035567/bt5346sup1.cif

e-66-o2593-sup1.cif^{(22.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810035567/bt5346Isup2.hkl

e-66-o2593-Isup2.hkl^{(157.1KB, hkl)}

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
N2—H2B⋯O1ⁱ	0.86	1.91	2.759 (3)	171
C33—H33⋯N11ⁱⁱ	0.93	2.72	3.402 (4)	131
C52—H52⋯Cl2ⁱⁱⁱ	0.93	2.97	3.897 (3)	174
C54—H54⋯N11^iv	0.93	2.72	3.541 (4)	147

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

Acknowledgments

SAB sincerely thank the Vice Chancellor and Management of Kalasalingam University, Anand Nagar, Krishnan Koil, for their support and encouragement. SA thanks the Vice Chancellor of Anna University of Technology, Tirunelveli, for his support and encouragement.

supplementary crystallographic information

Comment

Alkenes undergo co-halogenation reactions to afford bifunctional compounds which serve as potential synthons towards the synthesis of various heterocyclic compounds (Rodriguez & Dulcere, 1993). The regio/stereoselectivity of such addition reactions is governed by various factors, one being structural features of the alkene. We were interested in investigating some of the structure features in the title compound, which may alter the regio/stereoselectivity in addition reactions.

The molecular structure of the title compound is shown in Fig. 1. The cyclohexene ring is in a sofa conformation. Two phenyl rings are oriented with a dihedral angle of 54.8 (1)° to each other. Further, the dichlorophenyl rings are making dihedral angles of 66.7 (1)° and 84.3 (1)° with the phenyl rings of C31/C36 and C51/C56 respectively. The crystal structure is stabilized by intermolecular C—H···N, C—H···Cl and classical N—H···O hydrgeon bonds (Tab. 1). The packing diagram of the title compound is shown in Fig. 2.

A chain C(6) motif extending along the b axis of the unit cell is observed through classical N—H···O hydrogen bond (Fig.3). Centrosymmetric ring R₂²(16) motif is formed around the crystallographic inversion centre through C—H···Cl bond (Fig. 4). Further, another ring R₂²(18) motif is observed around crystallographic inversion centre through a C—H···N bond (Fig. 5). These ring motifs are connected along c axis of the unit cell through another C—H···N bond [C54—H54···N11(x, -y - 1/2, z - 1/2)].

Experimental

A mixture of 1,3-diphenylacetone 5 (1 mmol), 2-[(2,4-dichlorophenyl)methylene]malononitrile (1 mmol), and sodium ethoxide (2 mmol) was ground well in a mortar and pestle at ambient temperature for about 15–30 sec. Then water (50–70 ml) was added to the mixture and the product was filtered and washed with water, dried in vacuo and subjected to flash chromatographic purification employing flash silica gel (230–400 mesh) with petroleum ether-ethyl acetate mixture as eluent. The products were further recrystallized from ethanol-ethyl acetate mixture (1:2 v/v).