Antimalarials. 9. Methylthio- and methylsulfonyl-substituted 9-phenanthrenemethanols

Nine di- and trisubstituted 9-phenanthrenemethanols bearing methylthio and methylfulfonyl substituents in the 2 and/or 6 positions of the phenanthrene nucleus were prepared and screened for antimalarial activity against Plasmodium berghei in mice. Six of the nine compounds were curative at or below 160 mg/kg. The most active structures contained a methylthio substituent in combination with two chlorine atoms.