To a solution of 1 eq. of aromatic aldehyde in toluene, 1.25-100 eq. of the corresponding methylene component, 1 eq. of piperidine and 100 mg of molecular sieves 4Ȧ were added. The mixture was heated in inert atmosphere at 110 o C for 4-48h, the solvent was evaporated under reduced pressure. The crude product was purified by preparative TLC using toluene as the eluent to afford the desired compounds.