Synthesis and antiproliferative activity of RITA and its analogs

The synthesis of RITA and a variety of five-membered heterocyclic triads by the cyclocondensation of 1,4-bis(5-substituted-2-thienyl or 2-furyl)-1,3-butadiynes with water or Na2S·9H2O in the presence of KOH in DMSO is described. The study on the antiproliferative activities against K562, MCF-7, A549, and HCT116 tumor cells has revealed that some of the heterocyclic triads show higher antiproliferative activities than RITA, depending on the structures of substituents, the property of heteroatoms as well as their numbers.