2-Methoxy-6-(6-methyl-1H-benzimidazol-2-yl)phenol

In the title molecule, C15H14N2O2, the substituted benzene ring forms a dihedral angle of 4.15 (1)° with the benzimidazole ring system. An intramolecular O—H⋯N hydrogen bond generates an S(6) ring motif. In the solid state, molecules are linked into chains along the [001] via intermolecular bifurcated N—H⋯(O,O) hydrogen bonds, which generate R 1 2(5) ring motifs. The crystal packing is also consolidated by C—H⋯π interactions, and π–π stacking interactions between the imidazole and substituted benzene rings [centroid–centroid distance = 3.5746 (13) Å]. The methyl group attached to the benzimidazole ring system is disordered over two positions with occupancies of 0.587 (6) and 0.413 (6), suggesting 180° rotational disorder for the benzimidazole group.

In the title molecule, C 15 H 14 N 2 O 2 , the substituted benzene ring forms a dihedral angle of 4.15 (1) with the benzimidazole ring system. An intramolecular O-HÁ Á ÁN hydrogen bond generates an S(6) ring motif. In the solid state, molecules are linked into chains along the [001] via intermolecular bifurcated N-HÁ Á Á(O,O) hydrogen bonds, which generate R 1 2 (5) ring motifs. The crystal packing is also consolidated by C-HÁ Á Á interactions, andstacking interactions between the imidazole and substituted benzene rings [centroidcentroid distance = 3.5746 (13) Å ]. The methyl group attached to the benzimidazole ring system is disordered over two positions with occupancies of 0.587 (6) and 0.413 (6), suggesting 180 rotational disorder for the benzimidazole group.

Experimental
To a solution of 4-methyl-1,2-phenylenediamine (0.244 g, 2 mmol) in ethanol (30 ml) was added 3-methoxysalicylaldehyde (0.604 g, 4 mmol). The mixture was refluxed with stirring for half an hour. The resultant red solution was filtered. The red powder obtained was dissolved in dichloromethane. Crystals suitable for XRD were formed after several days of slow evaporation of solvent at room temperature.

Refinement
Atoms H1O and H1N were located in a difference Fourier map and refined freely. The remaining H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 or 0.96 Å and U iso (H) = 1.2 or 1.5 U eq (C). A rotating-group model was applied for the methyl groups. The methyl group attached to the benzimidazole ring system is disordered over two positions with refined site-occupancies of 0.587 (6) and 0.413 (6). The U ij components of the atom C3 were approximated to isotropic behaviour. Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme. Intramolecular interactions are shown as dashed lines. Both disorder components are shown.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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.