Synthesis and antiprotozoal properties of pentamidine congeners bearing the benzofuran motif

Forty-eight cationically substituted pentamidine congeners possessing benzofuran rings were synthesized by a copper mediated heteroannulation of substituted o-iodophenols with phenyl acetylenes. Activities of compounds 1-48 against Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani and cytotoxicities for mammalian cells were influenced by the nature of cationic substituents, placement of the benzofuran fragment, and the length of the carbon linker between aromatic moieties. Several dications exhibited superior antiplasmodial and antileishmanial potencies compared to pentamidine.