Synthesis and structural determination of 3,5-bis(2-fluorobenzylidene)-4-piperidone analogs of curcumin

Analogs of cytotoxic compound 3,5-bis(2-fluorobenzylidene)-4-piperidone (1) were synthesized and their molecular structures were characterized by 1H, 13C NMR, ESI–MS, IR spectra and X-ray crystallography. The central ring of the piperidin-4-one ring assumes a sofa conformation with two benzylidene rings connected through E,E oriented groups. The compound 1 crystallized in triclinic space group P  1¯. In order to obtain potentially more efficacious compounds, three dimers of 3,5-bis(2-fluorobenzylidene)-4-piperidone were synthesized. The two molecules of 1 were conjugated together via NoxalylN (3), NfumarylN (4) or NDTPAN (5) linkers. Compound 3 crystallized in monoclinic space group P21/n.