Crystal structure and Hirshfeld surface analysis of (Z)-4-(4-hy-droxy-benzyl-idene)-3-methyl-isoxazol-5(4H)-one.

The title compound, C(11)H(9)NO(3), contains an isoxazole and a hy-droxy-benzyl-idene ring, which are inclined to each another by 3.18†(8)°. There is an intra-molecular C-H⋯O contact forming an S(7) ring. In the crystal, mol-ecules stack head-to-tail in columns along the b-axis direction, linked by offset π-π inter-actions [inter-centroid distances of 3.676†(1) and 3.723†(1)†à ]. The columns are linked by O-H⋯O and O-H⋯N hydrogen bonds, forming layers parallel to the ab plane. The layers are linked by C-H⋯O hydrogen bonds, forming a supra-molecular three-dimensional framework. An analysis of the Hirshfeld surfaces points to the importance of the O-H⋯O and O-H⋯N hydrogen bonding in the packing mechanism of the crystal structure.