(E)-2-[4-(Piperidin-1-yl)benzyl-idene]-2,3-dihydro-1H-inden-1-one.

In the title compound, C(21)H(21)NO, the indene ring system is essentially planar with a maximum deviation of 0.066†(1)†à and makes dihedral angles of 7.93†(6) and 2.43†(6)°, respectively, with the benzene plane and the mean plane of the piperidine ring. These latter two planes make a dihedral angle of 7.61†(7)°. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, forming infinite chains along the b axis.