Synthesis of 3,4-dihydrothioxanthene-1,9-dione analogs as potential antimalarial agents

7-Chloro-3-(2,4-dichlorophenyl)-3,4-dihydro-1H-thioxanthene-1,9 (2H)-dione (10), and a variety of analogs and derivatives were prepared as sulfur isosteric analogs of the acridinedione antimalarial agent, floxacrine. The compounds were devoid of antimalarial activity against P. berghei in mice.