N'-[3-(Hy-droxy-imino)-butan-2-yl-idene]-4-methyl-benzene-1-sulfono-hydrazide.

In the title compound, C(11)H(15)N(3)O(3)S, the C-S-N(H)-N linkage is nonplanar, the torsion angle being 75.70 (12)°. The compound has two almost planar fragments linked to the S atom: the hydrazone-derivative fragment [(HONC(4)H(6))N-N(H)-] and the tolyl fragment (C(7)H(7)-) have maximum deviations from the mean plane through the non-H atoms of 0.0260 (10) and 0.0148 (14) Å, respectively. The two planar fragments make an inter-planar angle of 79.47 (5)°. In the crystal, mol-ecules are connected through inversion centers via pairs of N-H⋯O and O-H⋯N hydrogen bonds.