2-(1H-Benzotriazol-1-yl)-1-phenylethanol

In the title compound, C14H13N3O, the benzotriazole ring is oriented at a dihedral angle of 13.43 (4)° with respect to the phenyl ring. In the crystal structure, intermolecular O—H⋯N hydrogen bonds link the molecules into chains along the b axis. Aromatic π–π contacts between benzene rings and between triazole and benzene rings [centroid–centroid distances = 3.8133 (8) and 3.7810 (8) Å, respectively], as well as a weak C—H⋯π interaction involving the phenyl ring, are also observed.

In the title compound, C 14 H 13 N 3 O, the benzotriazole ring is oriented at a dihedral angle of 13.43 (4) with respect to the phenyl ring. In the crystal structure, intermolecular O-HÁ Á ÁN hydrogen bonds link the molecules into chains along the b axis. Aromaticcontacts between benzene rings and between triazole and benzene rings [centroid-centroid distances = 3.8133 (8) and 3.7810 (8) Å , respectively], as well as a weak C-HÁ Á Á interaction involving the phenyl ring, are also observed.   Table 1 Hydrogen-bond geometry (Å , ).
In the molecule of the title compound ( Fig. 1), bond lengths and angles are generally within normal ranges. The planar benzotriazole ring system is oriented with respect to the phenyl ring at a dihedral angle of 13.43 (4)°. Exocyclic carbon atoms C7 and C8 are 0.062 (1) and -0.028 (1) Å away from the planes of the benzotriazole and phenyl rings, respectively. So, they are almost coplanar with the adjacent rings.
In the crystal structure, intermolecular O-H···N hydrogen bonds (Table 1) link the molecules into chains along the b-axis ( Fig. 2), in which they may be effective in the stabilization of the structure. The π-π contacts between the benzene rings and between the triazole and the benzene rings , Cg2-Cg2 i and Cg1-Cg2 i [symmetry code: (i) 1 -x, 1 -y, -z, where Cg1 and Cg2 are centroids of the rings (C1/C6/N1-N3) and (C1-C6), respectively] with centroid-centroid distances of 3.8133 (8) and 3.7810 (8) Å are also observed in the crystal structure. respectively. A weak C-H···π interaction (Table 1) involving the phenyl ring also occurs.
A mixture of 2-(-benzotriazol-1-yl)-1-phenylethanone (500 mg, 2.10 mmol) and sodiumborohydride (159.5 mg, 4.21 mmol) in ethanol (25 ml) was refluxed for 4 h. After evaporation of the solvent, the mixture was neutralized with dilute HCl, and then refluxed for 30 min. After the mixture was cooled, the solution was alkalinized with dilute NaOH and the resulting precipitate was filtered. The filtrate was extracted with chloroform, then the organic phase was dried and evaporated. The residue was crystallized from ethyl acetate to obtain colorless crystals suitable for X-ray analysis (yield; 216 mg, 43%).

Refinement
H atoms were located in a difference Fourier map and refined isotropically.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Special details
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 > 2sigma(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.