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Acta Crystallogr Sect E Struct Rep Online. 2010 April 1; 66(Pt 4): o958.
Published online 2010 March 27. doi:  10.1107/S1600536810011013
PMCID: PMC2984039

N-(4-Chloro­phen­yl)ethanimidamide

Abstract

A twisted conformation is found in the title compound, C8H9ClN2, with the ethanimidamide residue being twisted substantially to the benzene ring [dihedral angle = 66.54 (14)°]. The conformation about the C=N double bond [1.299 (3) Å] is Z. A two-dimensional array with a zigzag topology is formed in the crystal structure via N—H(...)N and N—H(...)Cl hydrogen-bonding inter­actions.

Related literature

For background to the synthesis of N-(p-chloro­phen­yl)acetamidine and related N-aryl­acetamidines used as reagents in the formation of anti-leishmanial compounds, see: Shearer et al. (1997 [triangle]); Rousselet et al. (1993 [triangle]); Patai (1975 [triangle]). For background to leismaniasis, see: Ouellette et al. (2004 [triangle]); Croft et al. (2006 [triangle]); Ferreira et al. (2007 [triangle]); World Health Organization (2010 [triangle]).

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Object name is e-66-0o958-scheme1.jpg

Experimental

Crystal data

  • C8H9ClN2
  • M r = 168.62
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o958-efi1.jpg
  • a = 9.6460 (9) Å
  • b = 9.0192 (4) Å
  • c = 19.3281 (5) Å
  • V = 1681.53 (18) Å3
  • Z = 8
  • Mo Kα radiation
  • μ = 0.39 mm−1
  • T = 120 K
  • 0.35 × 0.20 × 0.10 mm

Data collection

  • Nonius KappaCCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 2007 [triangle]) T min = 0.792, T max = 1.000
  • 14006 measured reflections
  • 1924 independent reflections
  • 1185 reflections with I > 2σ(I)
  • R int = 0.081

Refinement

  • R[F 2 > 2σ(F 2)] = 0.047
  • wR(F 2) = 0.150
  • S = 1.05
  • 1924 reflections
  • 107 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.34 e Å−3
  • Δρmin = −0.33 e Å−3

Data collection: COLLECT (Hooft, 1998 [triangle]); cell refinement: DENZO (Otwinowski & Minor, 1997 [triangle]) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]) and DIAMOND (Brandenburg, 2006 [triangle]); software used to prepare material for publication: publCIF (Westrip, 2010 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011013/hg2664sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810011013/hg2664Isup2.hkl

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

Acknowledgments

The use of the EPSRC X-ray crystallographic service at the University of Southampton, England, and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES and FAPEMIG (Brazil).

supplementary crystallographic information

Comment

N-(p-Chlorophenyl)acetamidine and related N-arylacetamidines (Shearer et al. 1997; Rousselet et al. 1993; Patai, 1975) were synthesized for use as reagents in the formation of 5-(difluoromethyl)-2-methyl-1-(substituted-phenyl)-1H-imidazoles, which are active anti-leishmanial compounds (Ferreira et al., 2007). Leishmaniasis is caused by several species of protozoan parasites transmitted by the bite of the female phlebotomine sand fly. This neglected disease is currently prevalent in four continents, being endemic in 88 countries, 72 of which are developing countries, threatening 350 millions worldwide (World Health Organization, 2010). The treatment of Leishmaniasis, currently, is dependent on old and highly toxic drugs (Croft et al., 2006). In addition, the development of clinical resistance and the increase of co-infections leishmaniasis AIDS, in some countries is causing further worries. Thus, the development of new, efficient, and safe drugs for the treatment of this disease is imperative (Ouellette et al., 2004; Croft et al., 2006; Ferreira et al., 2007). This contribution describes the synthesis and crystallographic characterisation of an N-(p-chlorophenyl)acetamidine derivative, (I).

The molecular structure of (I), Fig. 1, is twisted about the C1–N1 bond as seen in the value of the C2–C1–N1–C7 torsion angle of -118.6 (2) °; the dihedral angle formed between the benzene ring and ethanimidamide residue is 66.54 (14) °. The molecule has approximate mirror symmetry with the non-hydrogen atoms of the ethanimidamide lying on the putative plane and the benzene ring being bisected by the plane. The conformation about the C7═ N1 double bond [1.299 (3) Å] is Z.

The crystal packing is dominated by N–H···N and N–H···Cl hydrogen bonding interactions, Table 1. These lead to the formation of 22-membered {···HNH···ClC4NCNH···ClC4N···HNCN}2 synthons that are connected into supramolecular arrays in the ac plane, Fig. 2; these have a zig-zag topology.

Experimental

To a stirred solution of p-chloroaniline (10.75 mmol) in acetonitrile (40 ml) was bubbled hydrogen chloride. A precipitate was formed immediately. The resulting suspension was refluxed and became homogeneous. Upon complete reaction, as shown by TLC, the mixture was rotary evaporated and the residue partitioned between CH2Cl2 and saturated aqueous NaHCO3. The aqueous layer was washed (3 times) with CH2Cl2, and the combined organic layers were dried over sodium sulfate, filtered, and the filtrate concentrated under reduced pressure to yield a white solid; yield 96%, m.p. 389–390 K. The sample used in the X-ray study was slowly grown from an ethanol solution of (I). IR (KBr, cm-1): 3451, 3295, 3079, 1640, 1586, 1482. 1H NMR (500 MHz, CDCl3): δ 1.99 (s, 3H, CH3); 4.53 (br s, 2H, 2); 6.77 (d, 2H, J = 8.0 Hz); 7.24 (d, 2H, J = 8.0 Hz) p.p.m. 13C NMR (125 MHz, CDCl3): δ 21.59 (CH3); 122.5 121.1; 128.6; 144.6; 155.3 (H2N—C=N) p.p.m. EI—MS (m/z): 168 (M+, 68%); 153 (M+-15, 38%); 127 (M+-41, 100%); 111 (M+ -57, 54%); 75 (M+-93, 42%).

Refinement

The C-bound H atoms were geometrically placed (C–H = 0.95–0.98 Å) and refined as riding with Uiso(H) = 1.2-1.5Ueq(C). The positions of the N–H atoms were refined with Uiso(H) = 1.2Ueq(N).

Figures

Fig. 1.
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
Fig. 2.
A view of a supramolecular array in (I) in the ac plane. The N–H···N and N–H···Cl hydrogen bonding interactions are shown as orange dashed lines. Colour code: Cl, cyan; N, blue; C, grey; ...

Crystal data

C8H9ClN2F(000) = 704
Mr = 168.62Dx = 1.332 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 2182 reflections
a = 9.6460 (9) Åθ = 2.9–27.5°
b = 9.0192 (4) ŵ = 0.39 mm1
c = 19.3281 (5) ÅT = 120 K
V = 1681.53 (18) Å3Block, colourless
Z = 80.35 × 0.20 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer1924 independent reflections
Radiation source: Enraf Nonius FR591 rotating anode1185 reflections with I > 2σ(I)
10 cm confocal mirrorsRint = 0.081
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.0°
[var phi] and ω scansh = −11→12
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)k = −11→9
Tmin = 0.792, Tmax = 1.000l = −25→21
14006 measured reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.150H atoms treated by a mixture of independent and constrained refinement
S = 1.05w = 1/[σ2(Fo2) + (0.081P)2] where P = (Fo2 + 2Fc2)/3
1924 reflections(Δ/σ)max = 0.001
107 parametersΔρmax = 0.34 e Å3
0 restraintsΔρmin = −0.33 e Å3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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)

xyzUiso*/Ueq
Cl10.43525 (8)0.20450 (7)0.43084 (3)0.0430 (3)
N10.36389 (19)0.4659 (2)0.71058 (10)0.0308 (5)
N20.1234 (2)0.4244 (2)0.70948 (11)0.0305 (5)
H1N0.044 (3)0.438 (3)0.7313 (13)0.037*
H2N0.124 (3)0.379 (3)0.6740 (14)0.037*
C10.3774 (2)0.4032 (3)0.64327 (12)0.0274 (6)
C20.4543 (2)0.2746 (3)0.63454 (14)0.0316 (6)
H20.49380.22720.67380.038*
C30.4741 (3)0.2144 (3)0.56933 (13)0.0317 (6)
H30.52660.12600.56380.038*
C40.4169 (2)0.2837 (3)0.51261 (13)0.0286 (6)
C50.3428 (3)0.4144 (3)0.51965 (12)0.0342 (6)
H50.30540.46270.48020.041*
C60.3243 (3)0.4736 (3)0.58491 (13)0.0348 (6)
H60.27450.56380.59010.042*
C70.2408 (2)0.4770 (3)0.73731 (13)0.0269 (6)
C80.2239 (3)0.5538 (3)0.80540 (14)0.0367 (6)
H8A0.31530.57060.82610.055*
H8B0.16800.49190.83640.055*
H8C0.17740.64920.79830.055*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cl10.0537 (5)0.0446 (5)0.0307 (4)0.0051 (3)0.0060 (3)−0.0034 (3)
N10.0210 (11)0.0449 (13)0.0264 (12)−0.0010 (9)−0.0007 (9)−0.0032 (9)
N20.0205 (11)0.0461 (14)0.0248 (12)−0.0033 (9)0.0019 (9)−0.0061 (10)
C10.0171 (11)0.0372 (14)0.0280 (14)−0.0036 (10)−0.0002 (10)0.0003 (11)
C20.0286 (13)0.0340 (14)0.0321 (15)−0.0010 (11)−0.0040 (11)0.0052 (11)
C30.0297 (13)0.0288 (13)0.0367 (16)0.0031 (10)0.0014 (11)0.0001 (11)
C40.0284 (13)0.0306 (15)0.0266 (14)−0.0016 (10)0.0072 (10)0.0012 (10)
C50.0327 (14)0.0437 (16)0.0263 (14)0.0074 (11)0.0018 (11)0.0068 (11)
C60.0296 (14)0.0403 (15)0.0345 (15)0.0119 (11)0.0047 (12)0.0019 (11)
C70.0233 (12)0.0329 (13)0.0246 (14)−0.0026 (10)−0.0006 (10)0.0029 (10)
C80.0281 (13)0.0512 (16)0.0307 (14)−0.0059 (12)0.0014 (11)−0.0066 (12)

Geometric parameters (Å, °)

Cl1—C41.743 (3)C3—C41.377 (4)
N1—C71.299 (3)C3—H30.9500
N1—C11.425 (3)C4—C51.385 (3)
N2—C71.340 (3)C5—C61.381 (3)
N2—H1N0.89 (3)C5—H50.9500
N2—H2N0.80 (3)C6—H60.9500
C1—C21.387 (3)C7—C81.496 (4)
C1—C61.393 (3)C8—H8A0.9800
C2—C31.386 (4)C8—H8B0.9800
C2—H20.9500C8—H8C0.9800
C7—N1—C1118.52 (19)C6—C5—C4119.1 (2)
C7—N2—H1N119.4 (17)C6—C5—H5120.5
C7—N2—H2N121 (2)C4—C5—H5120.5
H1N—N2—H2N119 (3)C5—C6—C1121.0 (2)
C2—C1—C6118.7 (2)C5—C6—H6119.5
C2—C1—N1119.5 (2)C1—C6—H6119.5
C6—C1—N1121.6 (2)N1—C7—N2125.8 (2)
C3—C2—C1120.8 (2)N1—C7—C8119.0 (2)
C3—C2—H2119.6N2—C7—C8115.2 (2)
C1—C2—H2119.6C7—C8—H8A109.5
C4—C3—C2119.4 (2)C7—C8—H8B109.5
C4—C3—H3120.3H8A—C8—H8B109.5
C2—C3—H3120.3C7—C8—H8C109.5
C3—C4—C5121.0 (2)H8A—C8—H8C109.5
C3—C4—Cl1119.65 (19)H8B—C8—H8C109.5
C5—C4—Cl1119.4 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N2—H1n···N1i0.88 (3)2.08 (3)2.965 (3)176 (3)
N2—H2n···Cl1ii0.80 (3)2.83 (3)3.464 (2)138 (3)

Symmetry codes: (i) x−1/2, y, −z+3/2; (ii) x−1/2, −y+1/2, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2664).

References

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Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography