(1R,2R,E,E)-N,N′-Bis(4-chloro­benzyl­idene)cyclo­hexane-1,2-diamine

Arvinnezhad, H.; Jadidi, K.; Notash, B.

doi:10.1107/S1600536812000724

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 2| February 2012| Pages o407-o408

doi:10.1107/S1600536812000724

Open

access

(1R,2R,E,E)-N,N′-Bis(4-chlorobenzylidene)cyclohexane-1,2-diamine

Hamid Arvinnezhad,^a Khosrow Jadidi ^a ^* and Behrouz Notash ^a

^aDepartment of Chemistry, Shahid Beheshti University, G. C., Evin, Tehran 1983963113, Iran
^*Correspondence e-mail: k-jadidi@sbu.ac.ir

(Received 2 January 2012; accepted 7 January 2012; online 14 January 2012)

The title Schiff base ligand, C₂₀H₂₀Cl₂N₂, was prepared by condensation of commercially available p-chlorobenzaldehyde and (R,R)-1,2-diammoniumcyclohexane mono-(+)-tartrate. The cyclohexane ring adopts a chair conformation. The dihedral angle between the two aromatic rings is 62.52 (8)°. The crystal structure is stabilized by an intermolecular C—H⋯Cl hydrogen bond.

Related literature

For the crystal structures of some Schiff bases derived from cyclohexane-1,2-diamine, see: Fan et al. (2011 ); Glidewell et al. (2005 ); Saleh Salga et al. (2010 ). For applications of chiral Schiff base ligands, see: Da Silva et al. (2011 ); Przybylski et al. (2009 ); Gupta & Sutar (2008 ); Dhar & Taploo (1982 ); Munslow et al. (2001 ); Gillespie et al. (2002 ); Kureshy et al. (2001 ); Takenaka et al. (2002 ). For the synthesis of the title compound, see: Larrow & Jacobsen (1998 ); Periasamy et al. (2001 ).

Experimental

Crystal data

C₂₀H₂₀Cl₂N₂
M_r = 359.28
Orthorhombic, P 2₁ 2₁ 2₁
a = 5.5058 (11) Å
b = 15.734 (3) Å
c = 21.302 (4) Å
V = 1845.4 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.36 mm⁻¹
T = 120 K
0.5 × 0.23 × 0.15 mm

Data collection

Stoe IPDS 2T diffractometer
12920 measured reflections
4973 independent reflections
4065 reflections with I > 2σ(I)
R_int = 0.088

Refinement

R[F² > 2σ(F²)] = 0.054
wR(F²) = 0.113
S = 1.13
4973 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.34 e Å⁻³
Absolute structure: Flack (1983 ), 2099 Friedel pairs
Flack parameter: −0.11 (7)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯Cl1ⁱ	0.97	2.81	3.525 (3)	131
Symmetry code: (i) $[-x+{\script{1\over 2}}, -y+2, z-{\script{1\over 2}}]$ .

Data collection: X-AREA (Stoe & Cie, 2005 ); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812000724/bt5777sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812000724/bt5777Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812000724/bt5777Isup3.cml

checkCIF report

Comment top

The class of chiral chelating Schiff bases are significant compounds in chemistry so that several reviews have been published on these substances (Da Silva et al., 2011; Przybylski et al., 2009; Gupta and Sutar 2008). Because of their stereochemical structures as well as their industrial properties (Dhar & Taploo, 1982) and potent biological activities (Da Silva et al., 2011; Przybylski et al., 2009) they are very attractive synthetic targets. Furthermore, it should be stressed that these useful and recyclable materials have been widely used in various enantioselective reactions, such as cyclopropanation (Munslow et al., 2001), aziridination (Gillespie et al., 2002), epoxidation (Kureshy et al., 2001), Diels-Alder reaction (Takenaka et al., 2002) as ligands or catalysts.

The asymmetric unit of the title compound which contains one molecule of related Schiff base compound is shown in Fig. 1. The reaction scheme for the synthesis of the title Schiff base is presented in Fig. 2. The bond distances and angles in the title compound are in agreement with related structures (Fan et al., 2011; Glidewell et al., 2005; Saleh Salga et al., 2010). The crystal structure is stabilized by an intermolecular C—H···Cl hydrogen bond (Fig. 3 & Table 1).

Related literature top

For the crystal structures of some Schiff bases derived from cyclohexane-1,2-diamine, see: Fan et al. (2011); Glidewell et al. (2005); Saleh Salga et al. (2010). For applications of chiral Schiff base ligands, see: Da Silva et al. (2011); Przybylski et al. (2009); Gupta & Sutar (2008); Dhar & Taploo (1982); Munslow et al. (2001); Gillespie et al. (2002); Kureshy et al. (2001); Takenaka et al. (2002). For the synthesis of the title compound, see: Larrow & Jacobsen (1998); Periasamy et al. (2001).

Experimental top

In a 25 ml two-necked round bottom flask with a reflux condenser, (R,R)-1,2-diammoniumcyclohexane mono-(+)-tartrate (2.64 g 10 mmol, 2 eq) and K₂CO₃ (2.76 g 20 mmol, 2 eq) were dissolved in H₂O (3 ml) (Larrow & Jacobsen 1998). The mixture was stirred and heated gently (~50 °C) for 10 min. Then a solution of p-chlorobenzaldehyde (2.8 g 20 mmol, 2 eq) in EtOH (10 ml) was poured in dropping funnel and added dropwise. The reaction mixture was stirred and refluxed for further 2 hrs. The mixture was cooled to room temperature and concentrated in vacuo. The residue was dissolved in CH₂Cl₂ (10 ml) and washed with saturated sodium bicarbonate (5 ml) and dried over Na₂SO₄. The organic layer was evaporated to yield crude product. Recrystallization in hot EtOH (7 ml) afford desired compound as colorless needles. 3.47 g, 97% yield, mp. 150 °C (mp 148–150°C), [α]²⁰ _D= -308° (c=1, CHCl₃) ([α]²⁰ _D= -136 (c=1, CHCl₃))(Periasamy et al., 2001).

Computing details top

Data collection: X-AREA (Stoe & Cie, 2005); cell refinement: X-AREA (Stoe & Cie, 2005); data reduction: X-AREA (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at 50% probability level.
	Fig. 2. The reaction scheme for the synthesis of the title compound.
	Fig. 3. The intermolecular C—H···Cl hydrogen bonds are shown as blue dashed lines.

(1R,2R,E,E)-N,N'-Bis(4- chlorobenzylidene)cyclohexane-1,2-diamine top

Crystal data top

C₂₀H₂₀Cl₂N₂	F(000) = 752
M_r = 359.28	D_x = 1.293 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 4973 reflections
a = 5.5058 (11) Å	θ = 2.3–29.2°
b = 15.734 (3) Å	µ = 0.36 mm⁻¹
c = 21.302 (4) Å	T = 120 K
V = 1845.4 (6) Å³	Needle, colorless
Z = 4	0.5 × 0.23 × 0.15 mm

Data collection top

Stoe IPDS 2T diffractometer	4065 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.088
Graphite monochromator	θ_max = 29.2°, θ_min = 2.3°
Detector resolution: 0.15 mm pixels mm^-1	h = −7→7
rotation method scans	k = −19→21
12920 measured reflections	l = −29→29
4973 independent reflections

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.054	w = 1/[σ²(F_o²) + (0.0326P)² + 0.5925P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.113	(Δ/σ)_max = 0.002
S = 1.13	Δρ_max = 0.29 e Å⁻³
4973 reflections	Δρ_min = −0.34 e Å⁻³
218 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0059 (11)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 2099 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.11 (7)

Crystal data top

C₂₀H₂₀Cl₂N₂	V = 1845.4 (6) Å³
M_r = 359.28	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 5.5058 (11) Å	µ = 0.36 mm⁻¹
b = 15.734 (3) Å	T = 120 K
c = 21.302 (4) Å	0.5 × 0.23 × 0.15 mm

Data collection top

Stoe IPDS 2T diffractometer	4065 reflections with I > 2σ(I)
12920 measured reflections	R_int = 0.088
4973 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.054	H-atom parameters constrained
wR(F²) = 0.113	Δρ_max = 0.29 e Å⁻³
S = 1.13	Δρ_min = −0.34 e Å⁻³
4973 reflections	Absolute structure: Flack (1983), 2099 Friedel pairs
218 parameters	Absolute structure parameter: −0.11 (7)
0 restraints

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	−0.02567 (12)	1.06658 (5)	0.95529 (3)	0.03732 (17)
Cl2	1.02450 (16)	0.61772 (5)	1.03022 (3)	0.0446 (2)
C9	0.5215 (5)	1.08153 (16)	0.83309 (11)	0.0302 (5)
H9	0.6498	1.1182	0.8246	0.036*
N2	0.9823 (4)	0.78245 (13)	0.73687 (9)	0.0292 (5)
C3	1.0135 (5)	0.91257 (17)	0.56137 (10)	0.0316 (5)
H3A	0.9729	0.9310	0.5192	0.038*
H3B	1.1598	0.9422	0.5742	0.038*
C18	0.9686 (5)	0.65212 (16)	0.95383 (11)	0.0333 (6)
N1	0.6607 (4)	0.92267 (14)	0.71446 (9)	0.0284 (5)
C12	0.1355 (5)	0.97300 (18)	0.85723 (11)	0.0293 (5)
H12	0.0050	0.9371	0.8655	0.035*
C8	0.4930 (5)	1.00840 (15)	0.79711 (10)	0.0258 (5)
C10	0.3615 (5)	1.10062 (18)	0.88148 (12)	0.0319 (6)
H10	0.3825	1.1493	0.9057	0.038*
C7	0.6765 (5)	0.98715 (16)	0.74955 (10)	0.0256 (5)
H7	0.8102	1.0228	0.7451	0.031*
C14	0.8364 (5)	0.73657 (17)	0.76733 (12)	0.0302 (6)
H14	0.6916	0.7206	0.7482	0.036*
C11	0.1706 (5)	1.04590 (17)	0.89291 (11)	0.0279 (5)
C1	0.8652 (5)	0.90495 (16)	0.67300 (11)	0.0269 (5)
H1	1.0099	0.9347	0.6884	0.032*
C15	0.8846 (5)	0.70693 (17)	0.83196 (12)	0.0301 (6)
C2	0.8063 (5)	0.93512 (19)	0.60586 (11)	0.0301 (5)
H2A	0.6575	0.9083	0.5916	0.036*
H2B	0.7814	0.9962	0.6058	0.036*
C17	1.1362 (6)	0.70438 (18)	0.92486 (12)	0.0339 (6)
H17	1.2761	0.7210	0.9460	0.041*
C13	0.2957 (5)	0.95433 (17)	0.80948 (11)	0.0285 (6)
H13	0.2732	0.9057	0.7854	0.034*
C4	1.0598 (6)	0.81726 (19)	0.56146 (11)	0.0366 (6)
H4A	1.1963	0.8045	0.5343	0.044*
H4B	0.9183	0.7880	0.5451	0.044*
C5	1.1139 (6)	0.78524 (18)	0.62769 (12)	0.0349 (6)
H5A	1.1323	0.7239	0.6268	0.042*
H5B	1.2658	0.8096	0.6421	0.042*
C6	0.9115 (5)	0.80889 (17)	0.67350 (11)	0.0292 (6)
H6	0.7621	0.7792	0.6615	0.035*
C19	0.7602 (5)	0.6264 (2)	0.92339 (13)	0.0382 (7)
H19	0.6486	0.5912	0.9433	0.046*
C16	1.0941 (5)	0.73191 (17)	0.86384 (12)	0.0328 (6)
H16	1.2062	0.7672	0.8441	0.039*
C20	0.7205 (5)	0.65407 (19)	0.86231 (13)	0.0372 (6)
H20	0.5809	0.6368	0.8413	0.045*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0353 (3)	0.0513 (4)	0.0254 (2)	0.0067 (3)	0.0022 (3)	−0.0030 (3)
Cl2	0.0633 (5)	0.0419 (4)	0.0286 (3)	0.0112 (4)	0.0068 (3)	0.0108 (3)
C9	0.0313 (13)	0.0296 (12)	0.0298 (10)	−0.0005 (12)	−0.0019 (11)	−0.0020 (10)
N2	0.0323 (11)	0.0293 (10)	0.0260 (9)	−0.0006 (10)	−0.0026 (10)	0.0040 (8)
C3	0.0306 (13)	0.0398 (14)	0.0244 (10)	0.0026 (12)	0.0017 (11)	0.0063 (10)
C18	0.0463 (15)	0.0281 (12)	0.0257 (10)	0.0069 (13)	0.0033 (12)	0.0060 (10)
N1	0.0292 (11)	0.0311 (11)	0.0248 (9)	0.0003 (10)	−0.0013 (8)	−0.0026 (9)
C12	0.0284 (13)	0.0353 (14)	0.0242 (11)	−0.0005 (12)	−0.0041 (10)	0.0025 (11)
C8	0.0280 (13)	0.0271 (12)	0.0221 (9)	0.0014 (11)	−0.0050 (10)	0.0011 (8)
C10	0.0356 (14)	0.0317 (14)	0.0283 (11)	0.0033 (12)	−0.0057 (11)	−0.0058 (10)
C7	0.0286 (12)	0.0261 (12)	0.0223 (10)	−0.0007 (10)	−0.0018 (10)	0.0039 (10)
C14	0.0313 (14)	0.0307 (14)	0.0287 (12)	−0.0028 (12)	0.0007 (11)	0.0002 (11)
C11	0.0291 (12)	0.0340 (14)	0.0206 (10)	0.0089 (11)	−0.0021 (10)	0.0017 (10)
C1	0.0267 (12)	0.0299 (13)	0.0240 (10)	−0.0016 (11)	0.0006 (10)	−0.0006 (10)
C15	0.0341 (13)	0.0268 (13)	0.0295 (12)	0.0005 (11)	0.0025 (11)	0.0038 (10)
C2	0.0307 (12)	0.0337 (14)	0.0259 (11)	0.0052 (12)	0.0000 (10)	0.0050 (11)
C17	0.0394 (15)	0.0322 (14)	0.0301 (13)	−0.0022 (13)	−0.0025 (11)	0.0001 (11)
C13	0.0346 (13)	0.0285 (13)	0.0225 (10)	−0.0002 (11)	−0.0058 (10)	0.0001 (10)
C4	0.0426 (16)	0.0417 (15)	0.0253 (11)	0.0037 (14)	0.0015 (11)	−0.0037 (11)
C5	0.0404 (16)	0.0330 (14)	0.0312 (13)	0.0088 (13)	0.0005 (12)	0.0006 (11)
C6	0.0341 (14)	0.0299 (13)	0.0235 (11)	0.0002 (12)	−0.0031 (10)	0.0020 (10)
C19	0.0355 (15)	0.0385 (16)	0.0405 (14)	−0.0014 (13)	0.0086 (12)	0.0122 (13)
C16	0.0362 (15)	0.0300 (14)	0.0323 (13)	−0.0047 (12)	0.0008 (11)	0.0062 (11)
C20	0.0313 (14)	0.0388 (16)	0.0415 (15)	−0.0053 (13)	0.0012 (12)	0.0060 (13)

Geometric parameters (Å, º) top

Cl1—C11	1.743 (3)	C14—C15	1.478 (4)
Cl2—C18	1.742 (2)	C14—H14	0.9300
C9—C10	1.389 (4)	C1—C6	1.533 (4)
C9—C8	1.391 (3)	C1—C2	1.541 (3)
C9—H9	0.9300	C1—H1	0.9800
N2—C14	1.260 (3)	C15—C20	1.388 (4)
N2—C6	1.466 (3)	C15—C16	1.395 (4)
C3—C4	1.521 (4)	C2—H2A	0.9700
C3—C2	1.525 (3)	C2—H2B	0.9700
C3—H3A	0.9700	C17—C16	1.390 (3)
C3—H3B	0.9700	C17—H17	0.9300
C18—C19	1.379 (4)	C13—H13	0.9300
C18—C17	1.382 (4)	C4—C5	1.527 (4)
N1—C7	1.263 (3)	C4—H4A	0.9700
N1—C1	1.458 (3)	C4—H4B	0.9700
C12—C13	1.378 (4)	C5—C6	1.527 (4)
C12—C11	1.389 (4)	C5—H5A	0.9700
C12—H12	0.9300	C5—H5B	0.9700
C8—C13	1.404 (4)	C6—H6	0.9800
C8—C7	1.469 (3)	C19—C20	1.390 (4)
C10—C11	1.380 (4)	C19—H19	0.9300
C10—H10	0.9300	C16—H16	0.9300
C7—H7	0.9300	C20—H20	0.9300

C10—C9—C8	121.1 (3)	C16—C15—C14	120.9 (2)
C10—C9—H9	119.5	C3—C2—C1	110.3 (2)
C8—C9—H9	119.5	C3—C2—H2A	109.6
C14—N2—C6	117.9 (2)	C1—C2—H2A	109.6
C4—C3—C2	110.7 (2)	C3—C2—H2B	109.6
C4—C3—H3A	109.5	C1—C2—H2B	109.6
C2—C3—H3A	109.5	H2A—C2—H2B	108.1
C4—C3—H3B	109.5	C18—C17—C16	119.5 (3)
C2—C3—H3B	109.5	C18—C17—H17	120.3
H3A—C3—H3B	108.1	C16—C17—H17	120.3
C19—C18—C17	121.4 (2)	C12—C13—C8	120.3 (2)
C19—C18—Cl2	119.7 (2)	C12—C13—H13	119.9
C17—C18—Cl2	119.0 (2)	C8—C13—H13	119.9
C7—N1—C1	117.3 (2)	C3—C4—C5	111.0 (2)
C13—C12—C11	119.4 (3)	C3—C4—H4A	109.4
C13—C12—H12	120.3	C5—C4—H4A	109.4
C11—C12—H12	120.3	C3—C4—H4B	109.4
C9—C8—C13	119.0 (2)	C5—C4—H4B	109.4
C9—C8—C7	119.4 (2)	H4A—C4—H4B	108.0
C13—C8—C7	121.5 (2)	C6—C5—C4	111.6 (2)
C11—C10—C9	118.6 (2)	C6—C5—H5A	109.3
C11—C10—H10	120.7	C4—C5—H5A	109.3
C9—C10—H10	120.7	C6—C5—H5B	109.3
N1—C7—C8	122.9 (2)	C4—C5—H5B	109.3
N1—C7—H7	118.5	H5A—C5—H5B	108.0
C8—C7—H7	118.5	N2—C6—C5	109.0 (2)
N2—C14—C15	123.1 (3)	N2—C6—C1	109.3 (2)
N2—C14—H14	118.4	C5—C6—C1	110.9 (2)
C15—C14—H14	118.4	N2—C6—H6	109.2
C10—C11—C12	121.6 (2)	C5—C6—H6	109.2
C10—C11—Cl1	119.3 (2)	C1—C6—H6	109.2
C12—C11—Cl1	119.0 (2)	C18—C19—C20	118.6 (3)
N1—C1—C6	108.2 (2)	C18—C19—H19	120.7
N1—C1—C2	109.9 (2)	C20—C19—H19	120.7
C6—C1—C2	110.2 (2)	C17—C16—C15	120.4 (3)
N1—C1—H1	109.5	C17—C16—H16	119.8
C6—C1—H1	109.5	C15—C16—H16	119.8
C2—C1—H1	109.5	C15—C20—C19	121.5 (3)
C20—C15—C16	118.7 (2)	C15—C20—H20	119.3
C20—C15—C14	120.4 (3)	C19—C20—H20	119.3

C10—C9—C8—C13	1.3 (4)	C9—C8—C13—C12	−1.0 (4)
C10—C9—C8—C7	−175.4 (2)	C7—C8—C13—C12	175.6 (2)
C8—C9—C10—C11	−0.7 (4)	C2—C3—C4—C5	−56.8 (3)
C1—N1—C7—C8	−174.9 (2)	C3—C4—C5—C6	55.3 (3)
C9—C8—C7—N1	−178.8 (2)	C14—N2—C6—C5	−127.0 (3)
C13—C8—C7—N1	4.6 (4)	C14—N2—C6—C1	111.7 (3)
C6—N2—C14—C15	−178.9 (2)	C4—C5—C6—N2	−175.6 (2)
C9—C10—C11—C12	−0.2 (4)	C4—C5—C6—C1	−55.2 (3)
C9—C10—C11—Cl1	177.6 (2)	N1—C1—C6—N2	−63.4 (3)
C13—C12—C11—C10	0.5 (4)	C2—C1—C6—N2	176.4 (2)
C13—C12—C11—Cl1	−177.32 (19)	N1—C1—C6—C5	176.4 (2)
C7—N1—C1—C6	138.6 (2)	C2—C1—C6—C5	56.2 (3)
C7—N1—C1—C2	−101.0 (3)	C17—C18—C19—C20	0.0 (4)
N2—C14—C15—C20	−177.8 (3)	Cl2—C18—C19—C20	−179.5 (2)
N2—C14—C15—C16	2.7 (4)	C18—C17—C16—C15	−0.1 (4)
C4—C3—C2—C1	58.1 (3)	C20—C15—C16—C17	−0.2 (4)
N1—C1—C2—C3	−176.9 (2)	C14—C15—C16—C17	179.3 (3)
C6—C1—C2—C3	−57.8 (3)	C16—C15—C20—C19	0.4 (4)
C19—C18—C17—C16	0.2 (4)	C14—C15—C20—C19	−179.1 (3)
Cl2—C18—C17—C16	179.7 (2)	C18—C19—C20—C15	−0.3 (4)
C11—C12—C13—C8	0.1 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···Cl1ⁱ	0.97	2.81	3.525 (3)	131

Symmetry code: (i) −x+1/2, −y+2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₂₀H₂₀Cl₂N₂
M_r	359.28
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	120
a, b, c (Å)	5.5058 (11), 15.734 (3), 21.302 (4)
V (Å³)	1845.4 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.36
Crystal size (mm)	0.5 × 0.23 × 0.15

Data collection
Diffractometer	Stoe IPDS 2T diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	12920, 4973, 4065
R_int	0.088
(sin θ/λ)_max (Å⁻¹)	0.686

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.054, 0.113, 1.13
No. of reflections	4973
No. of parameters	218
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.29, −0.34
Absolute structure	Flack (1983), 2099 Friedel pairs
Absolute structure parameter	−0.11 (7)

Computer programs: X-AREA (Stoe & Cie, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···Cl1ⁱ	0.97	2.81	3.525 (3)	130.8

Symmetry code: (i) −x+1/2, −y+2, z−1/2.

Acknowledgements

The authors thank the Vice President of Research Affairs at Shahid Beheshti University, General Campus, for financial support.

References

Da Silva, C. M., Da Silva, D. L., Modolo, L. V., Alves, R. B., De Resende, M. A., Martins, C. V. B. & De Fátima, Â. (2011). J. Adv. Res. 2, 1–8. CrossRef Google Scholar
Dhar, D. N. & Taploo, C. L. (1982). J. Sci. Ind. Res. 41, 501–506. CAS Google Scholar
Fan, P., Ge, C., Zhang, X., Zhang, R. & Li, S. (2011). Acta Cryst. E67, o3399. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Gillespie, K. M., Sanders, C. J., O'Shaughnessy, P., Westmoreland, I., Thickitt, C. P. & Scott, P. (2002). J. Org. Chem. 67, 3450–3458. Web of Science CSD CrossRef PubMed CAS Google Scholar
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2005). Acta Cryst. E61, o1699–o1701. Web of Science CSD CrossRef IUCr Journals Google Scholar
Gupta, K. C. & Sutar, A. K. (2008). Coord. Chem. Rev. 252, 1420–1450. Web of Science CrossRef CAS Google Scholar
Kureshy, R. I., Khan, N. U. H., Abdi, S. H. R., Patel, S. T. & Jasra, R. V. (2001). Tetrahedron Lett. 42, 2915–2918. Web of Science CrossRef CAS Google Scholar
Larrow, J. F. & Jacobsen, E. N. (1998). Org. Synth. 75, 1–11. CAS Google Scholar
Munslow, I. J., Gillespie, K. M., Deeth, R. J. & Scott, P. (2001). Chem. Commun. pp. 1638–1639. Web of Science CSD CrossRef Google Scholar
Periasamy, M., Srinivas, G. & Suresh, S. (2001). Tetrahedron Lett. 42, 7123–7125. Web of Science CSD CrossRef CAS Google Scholar
Przybylski, P., Huczynski, A., Pyta, K., Brzezinski, B. & Bartl, F. (2009). Curr. Org. Chem. 13, 124–148. Web of Science CrossRef CAS Google Scholar
Saleh Salga, M., Khaledi, H., Mohd Ali, H. & Puteh, R. (2010). Acta Cryst. E66, o1095. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (2005). X-AREA and X-RED32. Stoe & Cie, Darmstadt,Germany. Google Scholar
Takenaka, N., Huang, Y. & Rawal, V. H. (2002). Tetrahedron, 58, 8299–8305. Web of Science CrossRef CAS Google Scholar