N-[(S)-1-(3,5-Dimethyl-2-hydroxyphenyl)ethyl]-N-[(R)-2-hydroxy-1-phenylethyl]ammonium chloride

In the title compound, C18H24NO2 +·Cl−, the absolute configuration of the new stereogenic centre (the C atom with a CH2OH substituent) was unambiguously determined to have an R configuration. The dihedral angle between the two aromatic rings is 30.82 (2)°. Intermolecular N—H⋯Cl and O—H⋯Cl hydrogen bonds and intramolecular N—H⋯O hydrogen bonds stabilize the crystal structure.

In the title compound, C 18 H 24 NO 2 + ÁCl À , the absolute configuration of the new stereogenic centre (the C atom with a CH 2 OH substituent) was unambiguously determined to have an R configuration. The dihedral angle between the two aromatic rings is 30.82 (2) . Intermolecular N-HÁ Á ÁCl and O-HÁ Á ÁCl hydrogen bonds and intramolecular N-HÁ Á ÁO hydrogen bonds stabilize the crystal structure.
We previously reported the preparation and the structure of several chiral aminophenols including two chiral ligands, which derived from (R)-(-)2-phenylglycine (Zhang et al., 2006a,b). As part of our continuing research on chiral aminophenols, we prepared a new aminoalkylphenol, namely, 2- In order to determine its structure, the corresponding hydrochloride derivative, (I), was synthesized. Herein we report the crystal structure of (I), the title compound.
As shown in Fig. 1, the absolute configuration of (I) is (R,S), its geometric parameters are similar to those found in our previously reported relevant aminophenylphenols (Zhang et al., 2006a,b), at the same time, selected bond lengths and angles of (I), including those of new stereogenic carbon center (C9), are reported in Table S1, so we can infer the absolute configuration of the aminoalkylphenol is also (R,S). The dihedral angle of the two aromatic rings (C1-C6 and C11-C18) is 30.82 (2)°.

Experimental
The title compound was prepared according to the procedure of Zhang et al. R-(-)-2-Phenylglycinol was prepared by the re- Demir et al., 1999). R-(-)-Phenylglycinol (0.27 g, 2 mmol) and 1-(2-hydroxy-3,5-dimethylphenyl)ethanone (0.33 g, 2 mmol) were dissolved in methanol (10 ml) and reacted at room temperature for 24 h. After removal of solvent, 10 ml THF was introduced and NaBH 4 (0.15 g, 4 mmol) was added at 273 K, the mixture was stirred at the temperature until the solution became colourless. The reaction was quenched with 5 M HCl and then neutralized with NaOH solution. The aqueous solution was extracted with chloroform, the organic layer was dried with anhydrous Na 2 SO 4 and then filtered.

Refinement
All H  Figures Fig. 1. The asymmetric unit of (I), shown with 30% probability displacement ellipsoids.   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.