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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 4| April 2010| Page o958
doi:10.1107/S1600536810011013

N-(4-Chloro­phen­yl)ethanimidamide

Nubia Boechat,a Warner B. Kover,b Sabrina B. Ferreira,a Solange M. S. V. Wardell,c James L. Wardelld‡ and Edward R. T. Tiekinke*

aFundaçao Oswaldo Cruz, Instituto de Tecnologia em Fármacos, Departamento de Síntese Orgânica, Manguinhos, CEP 21041250 Rio de Janeiro, RJ, Brazil, bUniversidade Federal do Rio de Janeiro, Departamento de Química Orgânica, Instituto de Química, Cidade Universitária, 21949-900 Rio de Janeiro, RJ, Brazil, cCHEMSOL, 1 Harcourt Road, Aberdeen AB15 5NY, Scotland, dCentro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Casa Amarela, Campus de Manguinhos, Av. Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil, and eDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: edward.tiekink@gmail.com

(Received 24 March 2010; accepted 24 March 2010; online 27 March 2010)

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[Shearer, B. G., Oplinger, J. A. & Lee, S. (1997). Tetrahedron Lett. 38, 179-182.]); Rousselet et al. (1993[Rousselet, G., Capdevielle, P. & Maumy, M. (1993). Tetrahedron Lett. 34, 6395-6398.]); Patai (1975[Patai, S. (1975). In The Chemistry of Amidines and Imidates. New York: Wiley.]). For background to leismaniasis, see: Ouellette et al. (2004[Ouellette, M., Drummelsmith, J. & Papadopoulou, B. (2004). Drug Resist. Update, 7, 257-266.]); Croft et al. (2006[Croft, S. L., Sundar, S. & Fairlamb, A. H. (2006). Clin. Microbiol. Rev. 19, 111-126.]); Ferreira et al. (2007[Ferreira, S. B., Costa, M. S., Boechat, B., Bezerra, R. J. S., Genestra, M. S., Canto-Cavalheiro, M. M., Kover, W. B. & Ferreira, V. F. (2007). Eur. J. Med. Chem. 42, 1388-1395.]); World Health Organization (2010[World Health Organization (2010). http://www.who.int/mediacentre/news/releases/2010/drug_resistant_tb_20100318/en/index.html .]).

[Scheme 1]

Experimental

Crystal data

  • C8H9ClN2

  • Mr = 168.62

  • Orthorhombic, P b c a

  • 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[Sheldrick, G. M. (2007). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.792, Tmax = 1.000

  • 14006 measured reflections

  • 1924 independent reflections

  • 1185 reflections with I > 2σ(I)

  • Rint = 0.081
Refinement

  • R[F2 > 2σ(F2)] = 0.047

  • wR(F2) = 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

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N2—H1n⋯N1i 0.88 (3) 2.08 (3) 2.965 (3) 176 (3)
N2—H2n⋯Cl1ii 0.80 (3) 2.83 (3) 3.464 (2) 138 (3)
Symmetry codes: (i) [x-{\script{1\over 2}}, y, -z+{\script{3\over 2}}]; (ii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1].

Data collection: COLLECT (Hooft, 1998[Hooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) and COLLECT; data reduction: DENZO and COLLECT; 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: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). publCIF. In preparation.]).

Supporting information

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

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

checkCIF report


Comment top

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.

Related literature top

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); Rousselet et al. (1993); Patai (1975). For background to leismaniasis, see: Ouellette et al. (2004); Croft et al. (2006); Ferreira et al. (2007); World Health Organization (2010).

Experimental top

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 top

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).

Computing details top

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

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
[Figure 2] 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; and H, green.
N-(4-Chlorophenyl)ethanimidamide top
Crystal data top
C8H9ClN2F(000) = 704
Mr = 168.62Dx = 1.332 Mg m−3
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 mm−1
c = 19.3281 (5) ÅT = 120 K
V = 1681.53 (18) Å3Block, colourless
Z = 80.35 × 0.20 × 0.10 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer		1924 independent reflections
Radiation source: Enraf Nonius FR591 rotating anode1185 reflections with I > 2σ(I)
10 cm confocal mirrors monochromatorRint = 0.081
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.0°
ϕ 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 top
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 = 1.05 w = 1/[σ2(Fo2) + (0.081P)2]
where P = (Fo2 + 2Fc2)/3
1924 reflections(Δ/σ)max = 0.001
107 parametersΔρmax = 0.34 e Å−3
0 restraintsΔρmin = −0.33 e Å−3
Crystal data top
C8H9ClN2V = 1681.53 (18) Å3
Mr = 168.62Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 9.6460 (9) ŵ = 0.39 mm−1
b = 9.0192 (4) ÅT = 120 K
c = 19.3281 (5) Å0.35 × 0.20 × 0.10 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer		1924 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2007)		1185 reflections with I > 2σ(I)
Tmin = 0.792, Tmax = 1.000Rint = 0.081
14006 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.150H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.34 e Å−3
1924 reflectionsΔρmin = −0.33 e Å−3
107 parameters
Special details top

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) top
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) top
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, º) top
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, º) top
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.

Experimental details

Crystal data
Chemical formulaC8H9ClN2
Mr168.62
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)120
a, b, c (Å)9.6460 (9), 9.0192 (4), 19.3281 (5)
V (Å3)1681.53 (18)
Z8
Radiation typeMo Kα
µ (mm−1)0.39
Crystal size (mm)0.35 × 0.20 × 0.10
Data collection
DiffractometerNonius KappaCCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2007)
Tmin, Tmax0.792, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections		14006, 1924, 1185
Rint0.081
(sin θ/λ)max (Å−1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.150, 1.05
No. of reflections1924
No. of parameters107
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.34, −0.33

Computer programs: , DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
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

‡Additional correspondence author, e-mail: j.wardell@abdn.ac.uk.

Acknowledgements

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).

References

First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
 First citationCroft, S. L., Sundar, S. & Fairlamb, A. H. (2006). Clin. Microbiol. Rev. 19, 111–126.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
 First citationFerreira, S. B., Costa, M. S., Boechat, B., Bezerra, R. J. S., Genestra, M. S., Canto-Cavalheiro, M. M., Kover, W. B. & Ferreira, V. F. (2007). Eur. J. Med. Chem. 42, 1388–1395.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationHooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
 First citationOtwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.  Google Scholar
 First citationOuellette, M., Drummelsmith, J. & Papadopoulou, B. (2004). Drug Resist. Update, 7, 257–266.  Web of Science CrossRef CAS Google Scholar
 First citationPatai, S. (1975). In The Chemistry of Amidines and Imidates. New York: Wiley.  Google Scholar
 First citationRousselet, G., Capdevielle, P. & Maumy, M. (1993). Tetrahedron Lett. 34, 6395–6398.  CrossRef CAS Web of Science Google Scholar
 First citationShearer, B. G., Oplinger, J. A. & Lee, S. (1997). Tetrahedron Lett. 38, 179–182.  CrossRef CAS Web of Science Google Scholar
 First citationSheldrick, G. M. (2007). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationWestrip, S. P. (2010). publCIF. In preparation.  Google Scholar
 First citationWorld Health Organization (2010). http://www.who.int/mediacentre/news/releases/2010/drug_resistant_tb_20100318/en/index.html .  Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 4| April 2010| Page o958
doi:10.1107/S1600536810011013
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