2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol methanol 1.13-solvate

In the main molecule of the title compound, C22H20N2O4·1.13CH4O, the dihedral angles between the benzimidazole plane and the two benzene rings are 80.53 (10) and 82.76 (10)°. The solvent molecules are disordered between three positions, with refined occupancies of 0.506 (13), 0.373 (13) and 0.249 (5). The crystal structure is stabilized by intermolecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds. The crystal studied was a merohedral twin [BASF ratio of 0.917 (1)/0.083 (1)].


Comment
In continuation of our crystallographic study of benzimidazole derivatives (Al-Douh et al., 2006, 2009, we present here the crystal structure of the title compound, (I).

Experimental
A 100-mL, three-necked, round-bottomed flask is equipped with a nitrogen inlet adapter, rubber septum, glass stopper, and a magnetic stirring bar. The flask is charged with 5 mL of dichloromethane and (608.61 mg, 0.004 mol) of o-vanillin, and then is cooled in an ice-water bath while a solution of (216.29 mg, 0.002 mol) of o-phenylenediamine in 5 mL of dichloromethane is added dropwise via syringe over 15 min. After 30 min, 10 g of anhydrous magnesium sulfate is added in one portion.
The ice-water bath is removed, and the reaction mixture is stirred at room temperature for 2hr. The resulting solution is allowed to cool to room temperature and then is cooled in an ice-water bath for 2 hr. Filtration provides the light yellowish powder. The single crystals suitable for X-ray diffraction were obtained by evaporation of methanol and dichloromethane (7:3) solvent at room temperature.

Refinement
All H atoms were geometrically positioned (C-H 0.93-0.97 Å, O-H 0.82 Å) and refined in a riding model approximation, with U iso (H) = 1.2 or 1.5 (C, O). The methanol solvent molecules were treated as disordered over three positions with refined site-occupancies of 0.506 (13), 0.373 (13) and 0.249 (5) with SUMP command equal to 1.0 (1). The crystal studied was a twin with the refined BASF ratio of 0.917 (1)/0.083 (1). During the data collection, the temperature was controlled according to the literature procedure (Cosier & Glazer, 1986). Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atomic numbering. The disordered methanol solvent molecules were omitted for clarity. Intramolecular hydrogen bonds are drawn as dashed lines.

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. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. supplementary materials sup-9 Fig. 1