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Acta Cryst. (2009). E65, o301    [ doi:10.1107/S1600536809001068 ]

2-(2-Thienyl)-4,5-dihydro-1H-imidazole

R. Kia, H.-K. Fun and H. Kargar

Abstract top

In title compound, C7H8N2S, the five-membered rings are twisted by a dihedral angle of 5.17 (10)°. Two intermolecular N-H...N and C-H...N hydrogen bonds to the same acceptor N atom form seven-membered rings, producing R21(7) ring motifs. These interactions link neighbouring molecules into one-dimensional chains extended along the c axis. The crystal structure is further stabilized by weak intermolecular C-H...[pi] interactions.

Comment top

Imidazoline derivatives are of great importance because they exhibit significant biological and pharmacological activities including antihypertensive (Blancafort 1978), antihyperglycemic (Chan 1993), antidepressive (Vizi 1986), antihypercholesterolemic (Li et al., 1996) and antiinflammatory properties (Ueno et al., 1995). These compounds are also used as catalysts and synthetic intermediates in some organic reactions (Corey & Grogan 1999). Due to these important applications of imidazolines, here we report the crystal structure of the title compound (I).

In the title compound (I) (Fig. 1), bond lengths (Allen et al. 1987) and angles are within the normal ranges and are comparable with the related structures (Stibrany et al. 2004; Kia et al., 2008). The two five-membered rings are not coplanar to each other and twisted by a dihedral angle of 5.17 (10)°. Two intermolecular N—H···N and C—H···N hydrogen bonds involving a nitrogen atom as an acceptor form seven-membered rings, producing, R12(7) ring motifs (Table 1). These interactions link neighbouring molecules into 1-D extended chains along the c axis (, Fig. 2). The crystal structure is further stabilized by weak intermolecular C—H···π interactions [C6—H6A···Cg1i and C6—H6B···Cg1ii: (i) -x, 1/2 + y, 3/2 - z, (ii) -1 + x, y, z; Cg1 is the centroid of the S1/C1–C4 thiophene ring.

Related literature top

For the values of bond lengths, see: Allen et al. (1987). For details of hydrogen-bond motifs, see: Bernstein et al. (1995). For a related structure and the synthesis, see, Kia et al. (2008); Stibrany et al. (2004). For the applications of imidazoline derivatives, see, for example: Blancafort (1978); Chan (1993); Vizi (1986); Li et al. (1996); Ueno et al. (1995); Corey & Grogan (1999).

Experimental top

The synthetic method was based on the previous work (Stibrany et al. 2004), except that 10 mmol of 2-cyano-thiophene and 40 mmol of ethylenediamine was used. Single crystals suitable for X-ray diffraction were obtained by evaporation of a toluene solution at room temperature.

Refinement top

The hydrogen atom bound to N1 was located from the difference Fourier map and constrained to refine with the respective parent atom, see Table 1. The rest of the hydrogen atoms were positioned gemetrically and refined in a riding model approximation with C—H = 0.95–0.99 Å and Uiso (H) = 1.2 Ueq (C).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) with atom labels and 50% probability ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The crystal packing of (I), viewed down the b-axis showing 1-D infinite chain along the c-axis by intermolecular N—H···N and C—H···N interactions. The intermolecular interactions are shown as dashed lines.
2-(2-Thienyl)-4,5-dihydro-1H-imidazole top
Crystal data top
C7H8N2SF(000) = 320
Mr = 152.21Dx = 1.424 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9869 reflections
a = 6.1321 (2) Åθ = 2.5–34.3°
b = 11.5663 (3) ŵ = 0.37 mm−1
c = 10.0098 (3) ÅT = 100 K
β = 90.154 (1)°Block, colourless
V = 709.95 (4) Å30.54 × 0.28 × 0.22 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3100 independent reflections
Radiation source: fine-focus sealed tube3040 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
φ and ω scansθmax = 35.0°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		h = −9→9
Tmin = 0.825, Tmax = 0.922k = −18→17
27675 measured reflectionsl = −15→15
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)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.128H-atom parameters constrained
S = 1.24 w = 1/[σ2(Fo2) + 1.7551P]
where P = (Fo2 + 2Fc2)/3
3100 reflections(Δ/σ)max < 0.001
91 parametersΔρmax = 0.62 e Å−3
0 restraintsΔρmin = −0.39 e Å−3
Crystal data top
C7H8N2SV = 709.95 (4) Å3
Mr = 152.21Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.1321 (2) ŵ = 0.37 mm−1
b = 11.5663 (3) ÅT = 100 K
c = 10.0098 (3) Å0.54 × 0.28 × 0.22 mm
β = 90.154 (1)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3100 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		3040 reflections with I > 2σ(I)
Tmin = 0.825, Tmax = 0.922Rint = 0.021
27675 measured reflectionsθmax = 35.0°
Refinement top
R[F2 > 2σ(F2)] = 0.050H-atom parameters constrained
wR(F2) = 0.128Δρmax = 0.62 e Å−3
S = 1.24Δρmin = −0.39 e Å−3
3100 reflectionsAbsolute structure: ?
91 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
xyzUiso*/Ueq
S10.46967 (8)0.14161 (4)0.59514 (4)0.01548 (10)
N20.0669 (2)0.29635 (14)0.61122 (15)0.0137 (2)
N10.0460 (2)0.30376 (14)0.83746 (14)0.0133 (2)
H1N10.05840.27240.90260.016*
C10.6387 (3)0.05389 (17)0.6858 (2)0.0180 (3)
H1A0.75420.01000.64820.022*
C20.5888 (3)0.05418 (16)0.81838 (19)0.0169 (3)
H2A0.66550.01030.88350.020*
C30.4092 (3)0.12742 (15)0.84860 (17)0.0136 (3)
H3A0.35300.13850.93600.016*
C40.3260 (3)0.18060 (14)0.73589 (16)0.0117 (3)
C50.1427 (3)0.26052 (14)0.72556 (16)0.0109 (3)
C6−0.1543 (3)0.36276 (17)0.79447 (17)0.0154 (3)
H6A−0.17240.43800.84030.018*
H6B−0.28490.31440.81010.018*
C7−0.1097 (3)0.37874 (16)0.64419 (17)0.0151 (3)
H7A−0.24230.36150.59120.018*
H7B−0.06340.45910.62520.018*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.01727 (19)0.01847 (19)0.01071 (17)0.00446 (15)0.00185 (13)−0.00026 (14)
N20.0153 (6)0.0161 (6)0.0098 (6)0.0027 (5)0.0003 (4)0.0009 (5)
N10.0148 (6)0.0170 (6)0.0080 (5)0.0029 (5)0.0016 (4)0.0004 (5)
C10.0166 (7)0.0181 (8)0.0192 (8)0.0057 (6)−0.0001 (6)−0.0015 (6)
C20.0186 (7)0.0155 (7)0.0167 (7)0.0029 (6)−0.0034 (6)0.0009 (6)
C30.0164 (7)0.0129 (7)0.0113 (6)−0.0001 (5)−0.0002 (5)0.0004 (5)
C40.0131 (6)0.0120 (6)0.0100 (6)0.0005 (5)−0.0003 (5)−0.0005 (5)
C50.0120 (6)0.0113 (6)0.0094 (6)−0.0011 (5)0.0005 (5)−0.0004 (5)
C60.0143 (7)0.0186 (7)0.0132 (7)0.0030 (6)0.0019 (5)0.0007 (6)
C70.0152 (7)0.0181 (7)0.0120 (7)0.0035 (6)0.0000 (5)0.0018 (5)
Geometric parameters (Å, º) top
S1—C11.7099 (19)C2—H2A0.9500
S1—C41.7239 (17)C3—C41.381 (2)
N2—C51.302 (2)C3—H3A0.9500
N2—C71.480 (2)C4—C51.459 (2)
N1—C51.364 (2)C6—C71.541 (2)
N1—C61.468 (2)C6—H6A0.9900
N1—H1N10.7501C6—H6B0.9900
C1—C21.362 (3)C7—H7A0.9900
C1—H1A0.9500C7—H7B0.9900
C2—C31.423 (3)
C1—S1—C491.82 (9)C5—C4—S1120.22 (12)
C5—N2—C7105.57 (14)N2—C5—N1116.78 (15)
C5—N1—C6107.14 (14)N2—C5—C4122.49 (15)
C5—N1—H1N1119.6N1—C5—C4120.71 (14)
C6—N1—H1N1124.2N1—C6—C7101.03 (13)
C2—C1—S1112.21 (14)N1—C6—H6A111.6
C2—C1—H1A123.9C7—C6—H6A111.6
S1—C1—H1A123.9N1—C6—H6B111.6
C1—C2—C3112.63 (16)C7—C6—H6B111.6
C1—C2—H2A123.7H6A—C6—H6B109.4
C3—C2—H2A123.7N2—C7—C6105.80 (14)
C4—C3—C2112.08 (15)N2—C7—H7A110.6
C4—C3—H3A124.0C6—C7—H7A110.6
C2—C3—H3A124.0N2—C7—H7B110.6
C3—C4—C5128.52 (15)C6—C7—H7B110.6
C3—C4—S1111.26 (13)H7A—C7—H7B108.7
C4—S1—C1—C2−0.16 (16)C6—N1—C5—N211.9 (2)
S1—C1—C2—C3−0.2 (2)C6—N1—C5—C4−169.73 (15)
C1—C2—C3—C40.5 (2)C3—C4—C5—N2−173.27 (18)
C2—C3—C4—C5179.52 (17)S1—C4—C5—N26.9 (2)
C2—C3—C4—S1−0.60 (19)C3—C4—C5—N18.5 (3)
C1—S1—C4—C30.44 (14)S1—C4—C5—N1−171.36 (13)
C1—S1—C4—C5−179.67 (15)C5—N1—C6—C7−17.79 (18)
C7—N2—C5—N10.6 (2)C5—N2—C7—C6−12.26 (19)
C7—N2—C5—C4−177.67 (15)N1—C6—C7—N218.12 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···N2i0.752.232.977 (2)171
C3—H3A···N2i0.952.603.482 (2)155
C6—H6A···Cg1ii0.992.893.539 (2)124
C6—H6B···Cg1iii0.992.833.691 (2)146
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x, y+1/2, −z+3/2; (iii) x−1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···N2i0.75002.23002.977 (2)171.00
C3—H3A···N2i0.95002.60003.482 (2)155.00
C6—H6A···Cg1ii0.99002.89003.539 (2)124.00
C6—H6B···Cg1iii0.99002.83003.691 (2)146.00
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x, y+1/2, −z+3/2; (iii) x−1, y, z.
Acknowledgements top

HKF and RK thanks the Malaysian Government and Universiti sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HK thanks PNU for the financial support. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

references
References top

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