An N-substituted triacetonediamine compound is prepared by reacting 4-amino-2,2,6,6-tetramethylpiperidine or a derivative thereof with a carbonyl compound in a reductive amination, wherein reductive conditions are established by conducting the reaction in the presence of hydrogen and in the presence of a supported catalyst, wherein the supported catalyst includes at least one metal M, wherein the metal M is selected from the group consisting of V, Cr, Mo, Mn, Ni, Pd, Pt, Fe, Ru, Os, Co, Rh, Ir, and Cu.