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.

(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.

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.