3-Methylamino-3-phenylpropan-1-ol

The title compound, C10H15NO, is an amino alcohol with the hydroxy group residing on the terminal C atom. Apart from the hydroxy group and the phenyl ring, all non-H atoms are almost coplanar. In the crystal, classical O—H⋯N and N—H⋯O hydrogen bonds connect the molecules into centrosymmetric dimers [R 2 2(12) descriptor] and tetrameric units [R 4 4(8) descriptor] as ring motifs, consolidating a three-dimensional network.

The title compound, C 10 H 15 NO, is an amino alcohol with the hydroxy group residing on the terminal C atom. Apart from the hydroxy group and the phenyl ring, all non-H atoms are almost coplanar. In the crystal, classical O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds connect the molecules into centrosymmetric dimers [R 2 2 (12) descriptor] and tetrameric units [R 4 4 (8) descriptor] as ring motifs, consolidating a threedimensional network.

Related literature
For the syntheses of amino alcohols from isoxazolidines, isoxazolines and isoxazolinium salts, see: DeShong & Leginus, (1983 (2002); Lubell et al. (1991). For hydrogen-bond motifs see: Bernstein et al. (1995). For standard bond lengths, see: Allen et al. (1987).  Table 1 Hydrogen-bond geometry (Å , ).  , 1983;Jäger & Buss, 1980;Jäger et al., 1985;Jäger & Colinas, 2002;Henneböhle et al., 2004;Jäger et al., 2010). The structures and conformations of previously synthesized amino alcohols were all assigned on the basis of analytical as well as IR, 13 C and 1 H NMR data. When the 2-methyl-3phenylisoxazolidine-3-carbonitrile was heated to reflux with lithium aluminium hydride in ether (abs.), the title compound I was formed in good yield. The starting isoxazolidine had been obtained from the corresponding N-methylisoxazolinium salt by cyanide addition (Henneböhle et al., 2004;Ibrahim, 2009;Jäger et al. 2010). The formation of the amino alcohol I was rationalized elsewhere (Ibrahim, 2009). The title compound I is already known from other routes (Lubell et al., 1991), yet, the crystal structure of I has not been published so far. We herein report the synthesis and the crystal structure of I, along with the supramolecular motifs present in the crystal lattice.

Experimental
The asymmetric unit of I consists of one amino alcohol molecule with bond distances and angles in the normal range (Allen et al., 1987). The molecule, a primary alcohol and a secondary amine, adopts a planar zigzag-chain conformation (C1/C2/C3/N1/C4 almost coplanar), with both the hydroxy and the phenyl group being out-of-plane. The hydroxy and the phenyl group enclose dihedral angles of -60.3 (4)° and -63.0 (3)°, respectively, with the atoms of the carbon-chain (hydroxyl-O1/phenyl-C5-C1-C2-C3), see Fig. 1. In the crystal structure, molecules are hydrogen-bonded through the hydroxy groups as well as the amino groups (Table 1) giving rise to a three-dimensional network. The cooperative hydrogen bonds (alternating between hydroxy and amino groups) connect the molecules into chains down the crystallographic a axis (Fig. 2). These chains consist of alternating centrosymmetric dimers, with each dimer further interacting through the hydroxyl and amino groups with the adjacent one to form tetrameric units (Fig. 2). In terms of graph-set description, the hydrogen-bonded molecules might be described as forming two types of rings (Bernstein et al., 1995), the centrosymmetric dimers being R 2 2 (12) while R 4 4 (8) represents the descriptor for the tetramer units. These interactions consolidate a three-dimensional network.
This amino alcohol conformation in the crystal found here is in contrast to the conformations elucidated in solution on the basis of IR dilution experiments and extensive collections of 13 C and 1 H NMR data, notably coupling constants and substituent increments -there intramolecular hydrogen bonds O-H···N prevail to form monomers with chair-like arrangements (Jäger & Buss, 1980).
The mixture was allowed to warm up to room temperature and stirred for 1 h.

Refinement
Hydrogen atoms were located from the difference fourier map, but refined with fixed individual displacement parameters, using a riding model with d(C-H) ranging from 0.93 to 0.98 Å and U iso (H) = 1.2 U eq (C) or U iso (H) = 1.5 U eq (C methyl ). In addition, the methyl group is allowed to rotate but not to tip. Hydrogen atoms attached to the hydroxy function and to the amino moiety are refined freely because of their relevance in hydrogen bonding.

Figure 1
The molecular structure of I, with thermal ellipsoids drawn at the 30% probability level.