N'-[(E)-2-Hydroxy-benzyl-idene]-5-methyl-isoxazole-4-carbohydrazide monohydrate.

In the structure of the title compound, C(12)H(11)N(3)O(3)·H(2)O, the dihedral angle formed by the benzene and isoxazole rings is 2.03 (8)°. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond. In the crystal structure, mol-ecules are linked into a three-dimesional network by inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds, and by π-π stacking inter-actions involving adjacent benzene and isoxazole rings [centroid-centroid separation = 3.663 (2) Å].

(E)-N'-Benzyl-idene-5-methyl-isoxazole-4-carbohydrazide.

The mol-ecule of the title compound, C(12)H(11)N(3)O(2), is approximately planar with an r.m.s. deviation of 0.0814 Šfrom the plane through all the non-H atoms. The dihedral angle formed by the benzene and isoxazole rings is 6.88 (16)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯N hydrogen bond, forming an S(6) ring, and the mol-ecule displays an E configuration with respect to the C=N double bond. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds form centrosymmetric dimers which are further linked by weak C-H⋯N inter-actions augmented by very weak C-H⋯π contacts, forming layers parallel to (120).

5-Methyl-N'-(3-nitrobenzylidene)isoxazole-4-carbohydrazide.

The mol-ecule of the title compound, C(12)H(10)N(4)O(4), displays an E configuration about the C=N bond. The dihedral angle between the benzene and isoxazole rings is 1.36 (5)° and the mol-ecular conformation is stabilized by the an intra-molecular C-H⋯N hydrogen bond. In the crystal structure, centrosymmetrically related mol-ecules are connected by pairs of N-H⋯O hydrogen bonds into dimers, which are further linked into a three-dimensional network by inter-molecular C-H⋯O hydrogen bonds and by π⋯π stacking inter-actions involving adjacent benzene and isoxazole rings, with a centroid-centroid separation of 3.861 (3) Å.