Crystal structure of (E)-4-{[2-(2,4-di-nitro-phen-yl)hydrazin-1-yl-idene]meth-yl}-3-methyl-1-phenyl-5-(1H-pyrrol-1-yl)-1H-pyrazole.

The title compound, C21H17N7O4, is in an 'extended' conformation aided by an intra-molecular N-H⋯O hydrogen bond. The pyrazole ring makes dihedral angles of 29.17 (6), 65.47 (4) and 9.91 (7)°, respectively, with the phenyl, pyrrole and benzene rings. In the crystal, mol-ecules are connected by pairs of N-H⋯O and C-H⋯O hydrogen bonds, forming inversion dimers which associate into ribbons running along the b axis through complementary C-H⋯O inter-actions.