2,4-Diphenyl-4,5-dihydro-3H-pyrido[2,3-b][1,4]diazepine.

The asymmetric unit of the title compound, C20H17N3, contains two crystallographically independent mol­ecules (A and B). In mol­ecule A, the two benzene rings form dihedral angles of 74.12 (7) and 7.83 (7)° with the pyridine ring, while in mol­ecule B these angles are 77.48 (7) and 21.50 (7)°. The seven-membered heterocyclic ring adopts a boat conformation in both mol­ecules. In the crystal structure, each of the independent mol­ecules forms a centrosymmetric R22(8) dimer linked by paired N—H⋯N hydrogen bonds. The crystal structure is further stabilized by inter­molecular C—H⋯N hydrogen bonds and C—H⋯π inter­actions.