4-(2-Methoxybenzylidene)-2-phenyl-1,3-oxazol-5(4H)-one

The title molecule, C17H13NO3, adopts a Z configuration about the central olefinic bond. The 2-phenyl ring is almost coplanar with the plane of the oxazolone ring system, making a dihedral angle of 2.03 (11)°. The crystal structure is stabilized by π–π interactions between the oxazolone ring and phenyl ring of a neighbouring molecule [centroid–centroid distance = 3.550 (3)Å], and by two weak intermolecular C—H⋯π interactions. In addition, the crystal structure exhibits one weak intramolecular C—H⋯N hydrogen bond.

The title molecule ( Fig. 1) possesses normal geometric parameters (Allen et al., 1987) and adopts a Z configuration about the central olefinic bond. The C11-C16 phenyl ring makes a dihedral angle of 2.03 (11) ° with the plane of the oxazolone ring system. The molecular packing (Fig. 2) is stabilized by intermolecular π-π interactions between the oxazolone ring and phenyl ring of neighbouring molecules, with a Cg1···Cg3 iii distance of 3.550 (3) Å (Cg1 and Cg3 are the centroids of the O1/C10/N1/C8/C9 oxazolone ring and the C11-C16 phenyl ring; symmetry code as in Fig, 2). The crystal packing is further stabilized by two intermolecular C-H···π interactions; one between the H atom of methoxy group and the phenyl ring of a neighbouring molecule, a second between the H atom of methoxy group and the methoxyphenyl ring of an adjacent molecule, respectively ( Fig. 2 and Table 1; Cg2 is the centroid of the C1-C6 benzene ring, symmetry code as in Fig, 2).
Additionally, there is one intramolecular C-H···N hydrogen bond between a benzene-H atom and the N atom of oxazolone ring (Table 1 and Fig. 2).

Experimental
Anhydrous sodium acetate (2.1 g, 25.3 mmol) was added to a solution of 2-methoxybenzaldehyde (3.5 g, 25.7 mmol) and hippuric acid (7.7 g, 31.1 mmol) in acetic anhydride (2.1 g, 20.6 mmol). The reaction mixture was heated to 353 K and stirred under reflux conditions for the appropriate time 2 h. The reaction mixture was cooled to room temperature and ethanol (10 ml) was added. The mixture was stirred for 10 min until a yellow solid precipitated. The mixture was allowed to stand overnight, and then it was cooled in an ice bath. The crude azalactones were obtained after filtration and washing with hot water. Recrystallization from acetone/water afforded the pure azalactones as yellow crystals. [Yield (5.79 g, 91%), m.p.

Refinement
All H atoms were positioned geometrically with C-H = 0.93 and 0.96 Å and refined using a riding approximation model with U iso (H) = 1.2 or 1.5U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius.