In the title compound, C(20)H(20)N(4)O(2), the piperidine ring adopts a distorted boat conformation. The two phenyl rings form dihedral angles of 82.87 (1) and 84.40 (1)° with respect to the piperidine ring. The crystal packing is stabilized by inter-molecular C-H⋯O and C-H⋯N inter-actions.