Microwave-Assisted Solvent-Free Synthesis of Bis(dihydropyrimidinone)benzenes and Evaluation of their Cytotoxic Activity

An effective one-pot synthesis of bis(dihydropyrimidinonoe)benzenes using chlorotrimethylsilane (TMSCl) through Biginelli condensation reaction of terephthalic aldehyde, 1,3-dicarbonyl compounds and (thio)urea or guanidine under microwave irradiation conditions is described. Excellent yields of the products and simple work-up are attractive features of this green protocol. Then, the cytotoxic activities of these compounds were evaluated on five different human cancerous cell lines (Raji, HeLa, LS-180, SKOV-3 and MCF7). Their cytotoxic study indicated that they possessed a weak to moderate activity. Furthermore, the higher activity of compound 4b bearing sulfur in C-2 position of pyrimidinone ring showed the importance of this site for cytotoxic activity of these compounds.