2-p-Tolyl-4,5-dihydro-1H-imidazole

In the molecule of the title compound, C10H12N2, the six- and five-membered rings are almost co-planar, forming a dihedral angle of 3.56 (8)°. In the crystal structure, neighbouring molecules are linked together by intermolecular N—H⋯N hydrogen bonds into one-dimensional infinite chains along the c axis. The crystal structure, is further stabilized by weak intermolecular C—H⋯π and π–π stacking [centroid–centroid distance = 3.8892 (9) Å] interactions.

In the molecule of the title compound, C 10 H 12 N 2 , the six-and five-membered rings are almost co-planar, forming a dihedral angle of 3.56 (8) . In the crystal structure, neighbouring molecules are linked together by intermolecular N-HÁ Á ÁN hydrogen bonds into one-dimensional infinite chains along the c axis. The crystal structure, is further stabilized by weak intermolecular C-HÁ Á Á andstacking [centroid-centroid distance = 3.8892 (9) Å ] interactions.

Comment
Imidazoline derivatives are of great importance because they exhibit significant biological and pharmacological activities such as antihypertensive (Blancafort 1978), antihyperglycemic (Chan 1993), antidepressive (Vizi 1986), antihypercholesterolemic (Li et al., 1996) and antiinflammatory (Ueno et al., 1995). These compounds are also used as catalysts and synthetic intermediates in some organic reactions (Corey & Grogan 1999). With regards to the important applications of imidazolines, herein 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., 2008Kia et al., , 2009). The molecule is almost planar with a maximum deviation from the mean plane of the molecule for C2 atom being -0.176 (19) Å. The six-and five-membered rings are twisted from each other, forming the dihedral angle of 3.56 (8)°. The interesting feature of the crystal structure is the short C2···C10 i contact [3.368 (2) Å; (i) 1 + x, y, z], which is shorter than the sum of the van der Waals radius of carbon atom. In the crystal structure, neighbouring molecules are linked together by intermolecular N-H···N hydrogen bonds into 1-D infinite chains along the c axis (Table 1, Fig. 2). The crystal structure is further stabilized by weak intermolecular π-π stacking [Cg1···Cg2 iii = 3.8892 Å; (iii) -1 + x, y, z] and C-H···π interactions (Cg1 and Cg2 are the centroids of the N1/C2/C1/N2/C3-imidazoline and the benzene rings, respectiverly).

Experimental
The synthetic method was based on the previous work (Stibrany et al. 2004), except that 10 mmol of 4-methyl cyanobenzene and 40 mmol of ethylenediamine was used. Single crystals suitable for X-ray diffraction were obtained by evaporation of an methanol solution at room temperature.

Refinement
The N-bound hydrogen was located from the difference Fourier map are refined freely (see Table. 1). The rest of the hydrogen atoms were positioned geometrically with a riding approximation model with C-H = 0.93-0.97 Å and U iso (H) = 1.2 & 1.5 U eq (C). A rotating group model was applied for the methyl group. The 1120 Friedel pairs were merged before final refinement as there is not sufficient anomalous dispersion to determine the absolute structure. Fig. 1. The molecular structure of (I) with atom labels and 50% probability ellipsoids for non-H atoms.

2-p-Tolyl-4,5-dihydro-1H-imidazole
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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.