4-[(2-Hydroxynaphthalen-1-yl)(morpholin-4-yl)methyl]benzonitrile

The title compound, C22H20N2O2, was synthesized via a multicomponent reaction using naphthalen-2-ol, morpholine and 4-formylbenzonitrile. The dihedral angle between the naphthalene ring system and the benzene ring is 81.25 (10)°. The morpholine ring adopts a chair conformation. The molecular conformation is stabilized by intramolecular O—H⋯N and C—H⋯O hydrogen bonds. In the crystal, intermolecular C—H⋯N hydrogen bonds link molecules into helical chains running parallel to the c axis.

The title compound, C 22 H 20 N 2 O 2 , was synthesized via a multicomponent reaction using naphthalen-2-ol, morpholine and 4-formylbenzonitrile. The dihedral angle between the naphthalene ring system and the benzene ring is 81.25 (10) . The morpholine ring adopts a chair conformation. The molecular conformation is stabilized by intramolecular O-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds. In the crystal, intermolecular C-HÁ Á ÁN hydrogen bonds link molecules into helical chains running parallel to the c axis.
Compared to conventional multi-step organic syntheses, MCRs have advantages that include the simplicity of a one-pot procedure and the buildup of complex molecules (Domling & Ugi, 2000). We report here the synthesis and crystal structure of the title compound, 4-4-[(2-hydroxynaphthalen-1-yl)(morpholino)methyl]benzonitrile.

Experimental
A dry 100 ml flask was charged with 4-formylbenzonitrile (15 mmol), naphthalen-2-ol (15 mmol) and morpholine (15 mmol). The mixture was stirred at 373 K for 12 h, then ethanol (15 ml) was added. After heating under reflux for 1 h, the precipitate was filtrated out and washed with ethanol (10 ml × 3) to give the title compound. Colourless crystals were obtained by slow evaporation of a dichloromethane solution.

Refinement
All the H atoms attached to C atoms were situated into the idealized positions and treated as riding, with C-H = 0.93 Å (aromatic), 0.97 Å (methylene) and 0.98 Å (methine), and with U iso (H) = 1.2U eq (C). The hydroxyl H atom was located in a difference Fourier map and refined as riding, with O-H = 0.82 Å and with U iso (H) = 1.5U eq (O). Restraints (SIMU and DELU) were used for stabilizing the refinement of atoms C5 and C6. The quality of the crystal available was not optimal and it was weakly diffracting, with no significant data obtained beyond θ = 20°. Although recrystallization was attempted repeatedly, no better crystals could be obtained. This could account for the rather high R int value (0.138) and for the poor precision of the analysis.

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.