STUDIES ON ANALOGS OF QINGHAOSU (ARTEMISININE,ARTEANNUIN) IV. SYNTHESIS OF DERIVATIVES OF QINGHAOSU CONTAINING HALOGEN,NITROGEN AND SULFUR HETEROATOMS

In order to search for novel potent antimalarials, a series of ethers and esters of dihydroqinghaosu with halogen, nitrogen and sulfur heteroatoms substisuted in their side chain was prepared. However, these compounds did not show advantage over the corresponding unsubstituted derivatives except compound (17) which was found to be four times as active as m-methylbenzoic ester of dihydroqinghaosu. Compound(17)and(6)were ten times as active as qinghaosu against plasmodium berghei in mice.