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 C2 position of pyrimidinone ring showed the importance of this site for cytotoxic activity of these compounds.