5-Isobutyl-4-phenyl­sulfonyl-1H-pyrazol-3(2H)-one

The title compound, C(13)H(16)N(2)O(3)S, consists of two crystallographically independent mol­ecules with similar geometries and exists in a keto form, the C=O bond lengths being 1.267 (2) and 1.254 (2) Å. In both mol­ecules, the pyrazole rings are approximately planar, with maximum deviations of 0.017 (2) and 0.010 (2) Å, and the dihedral angles between the pyrazole and phenyl rings are 83.63 (11) and 70.07 (12)°. In one mol­ecule, an intra­molecular C—H⋯O hydrogen bond with an S(6) ring motif is observed. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into two-dimensional networks parallel to the ab plane.