Abstract The crystal structures of five N-arylpiperidin-4-one derivatives 2P2, 3P2, 5P2, 1P3, and 2P3 are presented (Fig. 2 and Tables 1–5) and discussed together with the derivatives 1P2 and 4P2 published previously. In all but one structure, 1P2, the aryl group is in an equatorial position. The piperidine ring adopts a normal chair conformation. In 1P2, the piperidine ring central C [BOND] C bonds are significantly elongated, which is consistent ...