10-(2-Ethoxy-1,3-thiazol-5-yl)-10-hydroxyphenanthren-9(10H)-one

In the title compound, C19H15NO3S, the dihydrophenanthrene unit is not planar, its central ring being distorted towards a sofa conformation. The essentially planar thiazole ring [maximum deviation = 0.005 (1) Å] is inclined at a dihedral angle of 85.29 (5)° with respect to the mean plane formed through the dihydrophenanthrene unit. In the crystal structure, pairs of intermolecular C—H⋯O hydrogen bonds link adjacent molecules into inversion dimers. Intermolecular O—H⋯N hydrogen bonds further interconnect these dimers into chains along the a axis. The crystal structure is further stabilized by weak intermolecular C—H⋯π interactions involving the thiazole ring.

In the title compound, C 19 H 15 NO 3 S, the dihydrophenanthrene unit is not planar, its central ring being distorted towards a sofa conformation. The essentially planar thiazole ring [maximum deviation = 0.005 (1) Å ] is inclined at a dihedral angle of 85.29 (5) with respect to the mean plane formed through the dihydrophenanthrene unit. In the crystal structure, pairs of intermolecular C-HÁ Á ÁO hydrogen bonds link adjacent molecules into inversion dimers. Intermolecular O-HÁ Á ÁN hydrogen bonds further interconnect these dimers into chains along the a axis. The crystal structure is further stabilized by weak intermolecular C-HÁ Á Á interactions involving the thiazole ring.

Comment
Phenanthraquinone and its derivatives have shown diverse applications and biological activities (Schuetzle, 1983;Cho et al., 2004;Lim et al., 1998;Sanbongi et al., 2003). 9,10-Phenanthraquinone has been used as o-quinone in photoreactions with various species (Shurygina et al., 2008;Zhang et al., 2004;Lichtenthaler et al., 2004). Thiazole-containing compounds, such as the mycothiazole (Cutignano et al.,2001), cystothiazole A (Williams et al.,2001;DeRoy & Charette,2003) and WS75624 B (Yoshimura et al.,1995;Tsuruni et al.,1995) have attracted considerable interest due to their potential application as bio-active species. Synthesis of organic molecules containing thiazole moieties therefore has been of current research interest (Gao et al.,2010;Shi et al.,2010;Kaleta et al.,2006). The title compound which contains phenanthraquinone and thiazole ring may has a potential use in biochemical and pharmaceutical fields. Due to the importance of the phenanthraquinone derivaties, we report in this paper the crystal structure of the title compound.
In the crystal structure ( Fig. 2), adjacent molecules are linked into dimers by pairs of intermolecular C12-H12A···O3 hydrogen bonds (Table 1). These dimers are interconnected by O2-H1O2···N1 hydrogen bonds (Table 1) into two-molecule-wide chains propagating along the a axis. Further stabilization of the crystal structure is provided by weak intermolecular C4-H4A···Cg1 interactions (Table 1) involving the centroid of the thiazole ring.

Experimental
The title compound was one of the products from the photoreaction between phenanthraquinone and 2-ethoxylthiazole. The compound was purified by flash column chromatography with ethyl acetate/petroleum ether (1:4) as eluents. X-ray quality single crystals of the title compound were obtained from slow evaporation of an acetone and petroleum ether (1:5) solution.

Refinement
The H atom bonded to O was located from difference Fourier map and allowed to refine freely. The remaining hydrogen atoms were placed in their calculated positions, with C-H = 0.93-0.97 Å, and refined using a riding model, with U iso (H) = 1.2 or 1.5U eq (C). The rotating group model was applied to the methyl group.  10-(2-Ethoxy-1,3-thiazol-5-yl)-10-hydroxyphenanthren-9(10H)-one

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.
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.