, with two molecules in the asymmetric unit. The naphthyridine ring system is almost planar and the six-membered piperidine ring adopts a chair conformation. Intramolecular N-H ...pi interactions are observed in the system with an N ...pi (phenyl centroid) distance of 3.619 (3) Angstrom, and C-H ...pi interactions between the naphthyridine molecule and the solvent are also observed.