The title compound, C21H19N3O3, has an E conformation about the azomethine double bond. The central moiety of the hydrazinecarboxamide moiety [-N-N-C(=O)-N-] has an almost coplanar arrangement [maximum deviation for the C atom = 0.010 (2) Å]. This central moiety is flanked by three aromatic rings and its mean plane makes dihedral angles of 24.7 (1), 72.91 (12) and 34.26 (11) Å, respectively, with the phenolic ring, the phenyl ring attached to the same C atom as the phenolic ring, and the phenyl-hydrazine ring. The adjacent phenolic and phenyl rings are twisted away from each other to reduce steric hindrance and make a dihedral angle of 80.59 (12)°. The phenolic and phenyl-hydrazine rings are inclined to one another by 28.89 (11)°. The rigidity of the mol-ecule is increased by an intra-molecular O-H⋯N hydrogen bond involving the phenolic hydrogen and the azomethine N atom. In the crystal, the carbonyl O atom forms bifurcated hydrogen bonds with the two NH atoms of the hydrazinic group, leading to the formation of chains propagating along [001]. Within the chains there are also C-H⋯O hydrogen bonds present. The chains are linked via C=O⋯π [3.4316 (18) Å] and parallel slipped π-π inter-actions, involving inversion-related benzene rings [centroid-centroid distance = 3.8850 (14) Å; inter-planar distance = 3.3895 (10) Å; slippage = 1.899 Å], forming sheets lying parallel to (100).
Keywords: C=O⋯π interactions; crystal structure; hydrazinecarboxamide; hydrogen bonding; supramolecular; π–π interactions.