2-[2-(5-Bromothiophen-2-yl)-4,5-diphenyl-1H-imidazol-1-yl]-3-phenylpropan-1-ol

In the title compound, C28H23BrN2OS, the dihedral angles formed by the imidazole ring with the 5-bromothiophenyl and phenyl rings are 76.90 (8), 34.02 (10) and 80.93 (11)°, respectively. The chiral centre maintains the S configuration of the l-phenylalaninol starting material. In the crystal, molecules are linked by O—H⋯N hydrogen bonds, forming chains running parallel to the a-axis direction.

In the title compound, C 28 H 23 BrN 2 OS, the dihedral angles formed by the imidazole ring with the 5-bromothiophenyl and phenyl rings are 76.90 (8), 34.02 (10) and 80.93 (11) , respectively. The chiral centre maintains the S configuration of the lphenylalaninol starting material. In the crystal, molecules are linked by O-HÁ Á ÁN hydrogen bonds, forming chains running parallel to the a-axis direction.   Table 1 Hydrogen-bond geometry (Å , ).
The molecular structure of the title compound is shown in Figure 1. As expected, the imidazole core (C7/C8/N2/C24/N1) is essentially planar, the maximum deviation being 0.008 (3) Å for atom C24. The dihedral angle between the 5-bromothiophenyl ring and imidazole ring is 76.90 (8)°. The dihedral angles between the two phenyl substituents (C1-C6, C9-C14) and the imidazole ring are 34.02 (10)° and 80.93 (11)°, respectively. The chiral C22 carbon atom maintains the S configuration of the L-phenylalaninol starting material. In the crystal, intermolecular O-H···N hydrogen bonds (Table 1) link molecules into chains running parallel to the a axis.

Experimental
The starting materials, L-phenylalaninol, benzil, ammonium acetate and 5-bromothiophene-2-carbaldehyde, are commercially available. In a three-neck round-bottomed flask fitted with a reflux condenser, L-phenylalaninol (0.76 g, 5 mmol), molar equivalents benzil, ammonium acetate and 5-bromothiophene-2-carbaldehyde were dissolved in CH 3 OH (30 mL). The mixture was kept at 65°C for 12 h. The resulting solution was cooled to room temperature and evaporation of the solvent gave the crude product. Crystallization of the crude product in CH 3 OH afforded colourless crystals of the title compound.

Refinement
The hydroxy H atom was located in a difference Fourier map and refined freely. All other H atoms were placed geometrically and refined as riding, with C-H = 0.93-0.98 Å, and with U iso (H) = 1.2 U eq (C).  The molecular structure of the title compound showing 30% probability displacement ellipsoids. Aromatic, methylene and methyne hydrogen atoms are omitted for clarity.

2-[2-(5-Bromothiophen-2-yl)-4,5-diphenyl-1H-imidazol-1-yl]-3-phenylpropan-1-ol
Crystal data C 28 H 23 BrN 2 OS M r = 515.45 Orthorhombic, P2 1 2 1 2 1 Hall symbol: P 2ac 2ab a = 9.36677 (18)   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 R-factors(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