rac-(S)-2-(1H-Imidazol-1-yl)-3-methylbutan-1-ol

In the crystal structure of the title compound, C8H14N2O, intermolecular O—H⋯N hydrogen bonds link molecules related by translation along the a axis into chains. Weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions enhance the crystal packing stability.

In the crystal structure of the title compound, C 8 H 14 N 2 O, intermolecular O-HÁ Á ÁN hydrogen bonds link molecules related by translation along the a axis into chains. Weak intermolecular C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions enhance the crystal packing stability.

rac-(S)-2-(1H-Imidazol-1-yl)-3-methylbutan-1-ol
G. Song, F. Xue and D. Li Comment Imidazole is important for biological systems, and its derivatives have attracted widespread interest due to their further expanded application in perfume chemistry and in the construction of some interesting metal-organic frameworks (Lu et al. 2006;Zou et al. 2006). Here, we report the crystal structure of the title compound, (I), which is a basic unit of constructing chiral receptors and could be applied for the preparation of perfume.
As shown in Fig. 1, there is a chiral center at C4 derived from the source L-valine. In the crystal, intermolecular O-H···N hydrogen bonds (Table 1) link the molecules related by translation along axis a into chains. Weak intermolecular C-H···O hydrogen bonds and C-H···π interactions (Table 1) enhance the crystal packing stability.

Experimental
The title compound was prepared according to the literature (Guo et al. 2006). Starting from L-valine, methyl 2-(1H-imidazol-1-yl)-3-methylbutanoate was easily prepared according to literature procedure (Bao et al. 2003). Following, NaBH 4 (1.52 g, 40 mmol) was added to methyl 2-(1H-imidazol-1-yl)-3-methylbutanoate (1.82 g, 10.0 mmol) in ethanol (50 ml) at 273 K during 30 min. The mixture was stirred at 333 K for another 20 h and then evaporated under vacuum. The residue was diluted with 50 ml saturated K 2 CO 3 and extracted with 30 ml ethyl acetate. The organic layer was dried over anhydrous Na 2 SO 4 and concentrated under reduced pressure. The resulting residue was purified by column chromatography on silica gel eluting with CH 2 Cl 2 /CH 3 OH (20/1, v/v). Then, colourless crystals suitable for X-ray analysis can be obtained by recrystallization of the compound from ethyl acetate.

Refinement
All H atoms were positioned geometrically and refined in the riding model approximation, with C-H = 0.93-0.98 Å and O-H = 0.82 Å, and U iso (H) = 1.2-1.5 U eq of the parent atom. Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids and the atomic numbering.

Figures
supplementary materials sup-2 rac-(S)-2-(1H-Imidazol-1-yl)-3-methylbutan-1-ol 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.