organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

1,4-Di­benzyl­piperazine

aInstitute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing 210042, People's Republic of China, and Jiangsu Qiang Lin Bio-Energy Co. Ltd, Liyang 213364, People's Republic of China
*Correspondence e-mail: zm205@sohu.com

(Received 3 November 2010; accepted 24 November 2010; online 27 November 2010)

In the title compound, C18H22N2, which possesses non-crystallographic inversion symmetry, the central piperazine ring adopts a chair conformation. The phenyl rings are not exactly parallel and make a dihedral angle of 1.3 (1)°. No significant inter­molecular contacts are observed in the crystal.

Related literature

For the properties and applications of piperazine derivatives, see: Zhao et al. (2002[Zhao, H., He, X., Thurkauf, A., Hoffman, D., Kieltyka, A., Brodbeck, R., Primus, R. & Wasley, J. W. F. (2002). Bioorg. Med. Chem. Lett. 12, 3111-3115.]); Sonurlikar et al. (1977[Sonurlikar, U. A., Shanker, B., Kirke, P. A. & Bhide, M. B. (1977). Bull. Haffkine, 5, 94-96.]); Bigoli et al. (2001[Bigoli, F., Chen, C. T., Wu, W. C., Deplano, P., Mercuri, M. L., Pellinghelli, M. A., Pilia, L., Pintus, G., Serpe, A. & Trogu, E. F. (2001). Chem. Commun. 21, 2246-2247.]). For the synthesis of related compounds, see: Zheng et al. (2005[Zheng, P.-W., Wang, W. & Duan, X.-M. (2005). Acta Cryst. E61, o2513-o2514.]); Sarangarajan et al. (2005[Sarangarajan, T. R., Panchanatheswaran, K., Low, J. N. & Glidewell, C. (2005). Acta Cryst. C61, o118-o121.]). For related structures, see: Yogavel et al. (2003[Yogavel, M., Selvanayagam, S., Velmurugan, D., Shanmuga Sundara Raj, S., Fun, H.-K., Marappan, M. & Kandaswamy, M. (2003). Acta Cryst. E59, o83-o85.]); Gunasekaran et al. (1996[Gunasekaran, K., Govindasamy, L., Shanmuga Sundara Raj, S., Velmurugan, D., Karunakaran, S. & Kandaswamy, M. (1996). Acta Cryst. C52, 1027-1028.]); Thiru­murugan et al. (1998[Thirumurugan, R., Shanmuga Sundara Raj, S., Shanmugam, G., Fun, H.-K., Marappan, M. & Kandaswamy, M. (1998). Acta Cryst. C54, 644-645.]).

[Scheme 1]

Experimental

Crystal data
  • C18H22N2

  • Mr = 266.38

  • Orthorhombic, P b c a

  • a = 7.5130 (15) Å

  • b = 19.127 (4) Å

  • c = 21.366 (4) Å

  • V = 3070.3 (11) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.07 mm−1

  • T = 293 K

  • 0.30 × 0.20 × 0.10 mm

Data collection
  • Enraf–Nonius CAD-4 diffractometer

  • Absorption correction: ψ scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.]) Tmin = 0.980, Tmax = 0.993

  • 5468 measured reflections

  • 2781 independent reflections

  • 1650 reflections with I > 2σ(I)

  • Rint = 0.045

  • 3 standard reflections every 200 reflections intensity decay: 1%

Refinement
  • R[F2 > 2σ(F2)] = 0.052

  • wR(F2) = 0.141

  • S = 1.01

  • 2781 reflections

  • 182 parameters

  • H-atom parameters constrained

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.13 e Å−3

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1989[Enraf-Nonius (1989). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Netherlands.]); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The structural study of piperazine derivatives is of interest, because some piperazine-containing derivatives constitute a novel class of mixed D2/D4 receptor antagonists (Zhao et al., 2002), and disubstituted piperazine derivatives are antifilarial, antiamoebic and spermicidal agents (Sonurlikar et al., 1977). In addition, piperazine derivatives are useful precursors of mixed-ligand dithiolenes of interest for non-linear optics (Bigoli et al., 2001). Recently, many piperazine derivatives with various substituents have been synthesized (Zheng et al., 2005; Sarangarajan et al., 2005). Herein, we report the crystal structure of the title compound, (I).

The geometry and labeling scheme of the title compound are depicted in Fig. 1, and the packing structure is given in Fig. 2. The piperazine ring exhibits a chair conformation with the usual bond lengths and angles (Yogavel et al., 2003), comparable with those of related reported structures (Gunasekaran et al., 1996; Thirumurugan et al., 1998).

Related literature top

For the properties and applications of piperazine derivatives, see: Zhao et al. (2002); Sonurlikar et al. (1977); Bigoli et al. (2001). For the synthesis of related compounds, see: Zheng et al. (2005); Sarangarajan et al. (2005). For related structures, see: Yogavel et al. (2003); Gunasekaran et al. (1996); Thirumurugan et al. (1998).

Experimental top

To a solution of anhydrous piperazine (5 mmol, 0.43 g) in CH2Cl2 (20 ml) was added 2.2 equivalents of triethylamine (1.5 ml), followed by benzyl bromide (10 mmol, 2.66 g) in CH2Cl2 (20 ml). After the mixture had been stirred for 10 min., the solvent was removed using a rotary evaporator. The solid residue was washed with water and recrystallized from ethanol-cyclohexane to give a colourless solid (76% yield). Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an ethanol solution.

Refinement top

All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å, and Uiso(H) = 1.2 Ueq of the carrier atom.

Structure description top

The structural study of piperazine derivatives is of interest, because some piperazine-containing derivatives constitute a novel class of mixed D2/D4 receptor antagonists (Zhao et al., 2002), and disubstituted piperazine derivatives are antifilarial, antiamoebic and spermicidal agents (Sonurlikar et al., 1977). In addition, piperazine derivatives are useful precursors of mixed-ligand dithiolenes of interest for non-linear optics (Bigoli et al., 2001). Recently, many piperazine derivatives with various substituents have been synthesized (Zheng et al., 2005; Sarangarajan et al., 2005). Herein, we report the crystal structure of the title compound, (I).

The geometry and labeling scheme of the title compound are depicted in Fig. 1, and the packing structure is given in Fig. 2. The piperazine ring exhibits a chair conformation with the usual bond lengths and angles (Yogavel et al., 2003), comparable with those of related reported structures (Gunasekaran et al., 1996; Thirumurugan et al., 1998).

For the properties and applications of piperazine derivatives, see: Zhao et al. (2002); Sonurlikar et al. (1977); Bigoli et al. (2001). For the synthesis of related compounds, see: Zheng et al. (2005); Sarangarajan et al. (2005). For related structures, see: Yogavel et al. (2003); Gunasekaran et al. (1996); Thirumurugan et al. (1998).

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1989); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the molecular structure of the title compound, showing displacement ellipsoids at the 30% probability level. Hydrogen atoms are drawn as spheres of arbitrary radius.
[Figure 2] Fig. 2. The packing of the title compound, viewed along the a axis.
1,4-Dibenzylpiperazine top
Crystal data top
C18H22N2Dx = 1.153 Mg m3
Mr = 266.38Melting point: 372 K
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 25 reflections
a = 7.5130 (15) Åθ = 9–13°
b = 19.127 (4) ŵ = 0.07 mm1
c = 21.366 (4) ÅT = 293 K
V = 3070.3 (11) Å3Strip, colorless
Z = 80.30 × 0.20 × 0.10 mm
F(000) = 1152
Data collection top
Enraf–Nonius CAD-4
diffractometer
1650 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.045
Graphite monochromatorθmax = 25.3°, θmin = 1.9°
ω/2θ scansh = 09
Absorption correction: ψ scan
(North et al., 1968)
k = 022
Tmin = 0.980, Tmax = 0.993l = 2525
5468 measured reflections3 standard reflections every 200 reflections
2781 independent reflections intensity decay: 1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.052H-atom parameters constrained
wR(F2) = 0.141 w = 1/[σ2(Fo2) + (0.065P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
2781 reflectionsΔρmax = 0.16 e Å3
182 parametersΔρmin = 0.13 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 constraintsExtinction coefficient: 0.0097 (11)
Primary atom site location: structure-invariant direct methods
Crystal data top
C18H22N2V = 3070.3 (11) Å3
Mr = 266.38Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 7.5130 (15) ŵ = 0.07 mm1
b = 19.127 (4) ÅT = 293 K
c = 21.366 (4) Å0.30 × 0.20 × 0.10 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
1650 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.045
Tmin = 0.980, Tmax = 0.9933 standard reflections every 200 reflections
5468 measured reflections intensity decay: 1%
2781 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0520 restraints
wR(F2) = 0.141H-atom parameters constrained
S = 1.01Δρmax = 0.16 e Å3
2781 reflectionsΔρmin = 0.13 e Å3
182 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.1744 (2)0.09152 (8)0.62991 (8)0.0427 (5)
C10.6103 (3)0.28645 (12)0.57631 (12)0.0604 (7)
H1A0.67520.32170.55690.073*
N20.1771 (2)0.03706 (8)0.61285 (8)0.0432 (5)
C20.5050 (3)0.24229 (12)0.54133 (10)0.0533 (6)
H2A0.49890.24770.49810.064*
C30.4087 (3)0.19002 (11)0.57034 (10)0.0449 (6)
H3A0.33820.16040.54630.054*
C40.4150 (3)0.18090 (10)0.63433 (10)0.0413 (5)
C50.5204 (3)0.22622 (11)0.66895 (11)0.0542 (6)
H5A0.52520.22180.71230.065*
C60.6185 (3)0.27799 (12)0.63953 (13)0.0634 (7)
H6A0.69080.30730.66320.076*
C70.3183 (3)0.12199 (11)0.66679 (10)0.0504 (6)
H7A0.40340.08550.67690.061*
H7B0.26960.13930.70590.061*
C80.0184 (3)0.13693 (10)0.62714 (10)0.0474 (6)
H8A0.05200.18190.60980.057*
H8B0.02680.14460.66910.057*
C90.1255 (3)0.10464 (10)0.58725 (10)0.0480 (6)
H9A0.22820.13540.58600.058*
H9B0.08240.09870.54480.058*
C100.0218 (3)0.00859 (10)0.61446 (10)0.0483 (6)
H10A0.02300.01540.57230.058*
H10B0.05510.05390.63130.058*
C110.1210 (3)0.02366 (10)0.65474 (10)0.0478 (6)
H11A0.07680.02930.69710.057*
H11B0.22350.00720.65620.057*
C120.3259 (3)0.00581 (11)0.57907 (10)0.0497 (6)
H12A0.28250.01320.53990.060*
H12B0.41160.04210.56920.060*
C130.4189 (3)0.05156 (10)0.61511 (9)0.0396 (5)
C140.5306 (3)0.09799 (11)0.58415 (10)0.0494 (6)
H14A0.54130.09540.54080.059*
C150.6260 (3)0.14791 (12)0.61664 (12)0.0569 (6)
H15A0.70120.17820.59520.068*
C160.6102 (3)0.15299 (11)0.68032 (12)0.0555 (6)
H16A0.67450.18660.70220.067*
C170.4989 (3)0.10828 (11)0.71169 (10)0.0505 (6)
H17A0.48700.11190.75490.061*
C180.4041 (3)0.05765 (11)0.67923 (10)0.0440 (6)
H18A0.32950.02740.70100.053*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0338 (10)0.0385 (10)0.0558 (11)0.0001 (8)0.0015 (8)0.0068 (8)
C10.0516 (15)0.0518 (15)0.0779 (18)0.0086 (12)0.0179 (14)0.0005 (14)
N20.0328 (9)0.0414 (10)0.0553 (11)0.0003 (9)0.0012 (9)0.0073 (9)
C20.0508 (14)0.0543 (14)0.0547 (14)0.0011 (13)0.0103 (12)0.0035 (11)
C30.0366 (12)0.0465 (13)0.0516 (14)0.0022 (10)0.0013 (10)0.0029 (11)
C40.0316 (11)0.0426 (12)0.0496 (13)0.0028 (10)0.0007 (10)0.0019 (10)
C50.0519 (15)0.0588 (15)0.0520 (14)0.0035 (13)0.0045 (12)0.0074 (11)
C60.0495 (15)0.0580 (16)0.0826 (19)0.0142 (13)0.0008 (13)0.0161 (14)
C70.0457 (13)0.0516 (13)0.0541 (13)0.0050 (11)0.0061 (12)0.0070 (11)
C80.0430 (13)0.0377 (11)0.0614 (14)0.0003 (11)0.0046 (11)0.0055 (11)
C90.0363 (13)0.0431 (13)0.0645 (14)0.0021 (10)0.0021 (11)0.0114 (11)
C100.0402 (13)0.0389 (12)0.0658 (15)0.0006 (10)0.0027 (11)0.0046 (11)
C110.0382 (12)0.0422 (13)0.0629 (14)0.0030 (10)0.0014 (11)0.0118 (11)
C120.0423 (13)0.0561 (14)0.0508 (13)0.0035 (11)0.0036 (11)0.0066 (11)
C130.0308 (11)0.0449 (12)0.0432 (12)0.0024 (10)0.0008 (10)0.0015 (10)
C140.0494 (14)0.0521 (14)0.0468 (12)0.0022 (12)0.0062 (11)0.0047 (11)
C150.0457 (14)0.0484 (14)0.0768 (17)0.0097 (12)0.0082 (12)0.0078 (13)
C160.0444 (14)0.0506 (14)0.0715 (17)0.0052 (12)0.0107 (12)0.0068 (12)
C170.0425 (14)0.0584 (14)0.0505 (13)0.0004 (12)0.0039 (11)0.0055 (11)
C180.0345 (12)0.0480 (13)0.0495 (13)0.0042 (10)0.0009 (10)0.0045 (10)
Geometric parameters (Å, º) top
N1—C111.458 (2)C8—H8B0.9700
N1—C71.459 (3)C9—H9A0.9700
N1—C81.460 (3)C9—H9B0.9700
C1—C61.362 (3)C10—C111.508 (3)
C1—C21.377 (3)C10—H10A0.9700
C1—H1A0.9300C10—H10B0.9700
N2—C91.456 (2)C11—H11A0.9700
N2—C101.457 (3)C11—H11B0.9700
N2—C121.459 (3)C12—C131.512 (3)
C2—C31.381 (3)C12—H12A0.9700
C2—H2A0.9300C12—H12B0.9700
C3—C41.379 (3)C13—C181.379 (3)
C3—H3A0.9300C13—C141.389 (3)
C4—C51.388 (3)C14—C151.381 (3)
C4—C71.509 (3)C14—H14A0.9300
C5—C61.385 (3)C15—C161.369 (3)
C5—H5A0.9300C15—H15A0.9300
C6—H6A0.9300C16—C171.371 (3)
C7—H7A0.9700C16—H16A0.9300
C7—H7B0.9700C17—C181.388 (3)
C8—C91.509 (3)C17—H17A0.9300
C8—H8A0.9700C18—H18A0.9300
C11—N1—C7111.26 (16)N2—C9—H9B109.7
C11—N1—C8108.88 (16)C8—C9—H9B109.7
C7—N1—C8112.29 (16)H9A—C9—H9B108.2
C6—C1—C2119.4 (2)N2—C10—C11109.76 (17)
C6—C1—H1A120.3N2—C10—H10A109.7
C2—C1—H1A120.3C11—C10—H10A109.7
C9—N2—C10109.14 (16)N2—C10—H10B109.7
C9—N2—C12112.43 (16)C11—C10—H10B109.7
C10—N2—C12112.31 (16)H10A—C10—H10B108.2
C1—C2—C3120.1 (2)N1—C11—C10110.62 (17)
C1—C2—H2A120.0N1—C11—H11A109.5
C3—C2—H2A120.0C10—C11—H11A109.5
C4—C3—C2121.2 (2)N1—C11—H11B109.5
C4—C3—H3A119.4C10—C11—H11B109.5
C2—C3—H3A119.4H11A—C11—H11B108.1
C3—C4—C5118.0 (2)N2—C12—C13113.54 (17)
C3—C4—C7122.24 (19)N2—C12—H12A108.9
C5—C4—C7119.7 (2)C13—C12—H12A108.9
C6—C5—C4120.6 (2)N2—C12—H12B108.9
C6—C5—H5A119.7C13—C12—H12B108.9
C4—C5—H5A119.7H12A—C12—H12B107.7
C1—C6—C5120.7 (2)C18—C13—C14117.88 (19)
C1—C6—H6A119.6C18—C13—C12122.00 (18)
C5—C6—H6A119.6C14—C13—C12120.04 (19)
N1—C7—C4113.99 (17)C15—C14—C13121.1 (2)
N1—C7—H7A108.8C15—C14—H14A119.5
C4—C7—H7A108.8C13—C14—H14A119.5
N1—C7—H7B108.8C16—C15—C14120.2 (2)
C4—C7—H7B108.8C16—C15—H15A119.9
H7A—C7—H7B107.6C14—C15—H15A119.9
N1—C8—C9110.77 (16)C15—C16—C17119.6 (2)
N1—C8—H8A109.5C15—C16—H16A120.2
C9—C8—H8A109.5C17—C16—H16A120.2
N1—C8—H8B109.5C16—C17—C18120.3 (2)
C9—C8—H8B109.5C16—C17—H17A119.9
H8A—C8—H8B108.1C18—C17—H17A119.9
N2—C9—C8109.98 (17)C13—C18—C17120.9 (2)
N2—C9—H9A109.7C13—C18—H18A119.5
C8—C9—H9A109.7C17—C18—H18A119.5
C6—C1—C2—C30.1 (3)C9—N2—C10—C1159.7 (2)
C1—C2—C3—C40.1 (3)C12—N2—C10—C11174.95 (16)
C2—C3—C4—C50.4 (3)C7—N1—C11—C10177.43 (17)
C2—C3—C4—C7176.9 (2)C8—N1—C11—C1058.3 (2)
C3—C4—C5—C61.2 (3)N2—C10—C11—N160.0 (2)
C7—C4—C5—C6176.1 (2)C9—N2—C12—C13162.08 (17)
C2—C1—C6—C50.9 (4)C10—N2—C12—C1374.4 (2)
C4—C5—C6—C11.5 (4)N2—C12—C13—C1820.0 (3)
C11—N1—C7—C4163.51 (17)N2—C12—C13—C14163.34 (18)
C8—N1—C7—C474.2 (2)C18—C13—C14—C151.0 (3)
C3—C4—C7—N119.8 (3)C12—C13—C14—C15175.73 (19)
C5—C4—C7—N1162.96 (18)C13—C14—C15—C160.8 (3)
C11—N1—C8—C957.9 (2)C14—C15—C16—C170.1 (3)
C7—N1—C8—C9178.46 (16)C15—C16—C17—C180.6 (3)
C10—N2—C9—C859.3 (2)C14—C13—C18—C170.5 (3)
C12—N2—C9—C8175.41 (17)C12—C13—C18—C17176.23 (19)
N1—C8—C9—N259.1 (2)C16—C17—C18—C130.4 (3)

Experimental details

Crystal data
Chemical formulaC18H22N2
Mr266.38
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)293
a, b, c (Å)7.5130 (15), 19.127 (4), 21.366 (4)
V3)3070.3 (11)
Z8
Radiation typeMo Kα
µ (mm1)0.07
Crystal size (mm)0.30 × 0.20 × 0.10
Data collection
DiffractometerEnraf–Nonius CAD-4
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.980, 0.993
No. of measured, independent and
observed [I > 2σ(I)] reflections
5468, 2781, 1650
Rint0.045
(sin θ/λ)max1)0.601
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.141, 1.01
No. of reflections2781
No. of parameters182
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.16, 0.13

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

 

Acknowledgements

This work was supported by the 948 program of the State Forestry Administration (2009–4–55).

References

First citationBigoli, F., Chen, C. T., Wu, W. C., Deplano, P., Mercuri, M. L., Pellinghelli, M. A., Pilia, L., Pintus, G., Serpe, A. & Trogu, E. F. (2001). Chem. Commun. 21, 2246–2247.  Web of Science CSD CrossRef Google Scholar
First citationEnraf–Nonius (1989). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands.  Google Scholar
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