A one-pot, efficient and facile synthesis of 4β-arylaminopodophyllotoxins: synthesis of NPF and GL-331 as DNA topoisomerase II inhibitors

A series of 4β-arylamino-4′-O-demethylepipodophyllotoxins and 4β-arylaminopodophyllotoxins have been synthesized with significant stereoselectivity and improved yields by employing the BF3·OEt2/NaI reagent system. Compounds NPF, GL-331 and other DNA topoisomerase II inhibitors have been prepared in good to excellent yields by employing this methodology.