Synthesis and antichagasic properties of new 1,2,6-thiadiazin-3,5-dione 1,1-dioxides and related compounds

In a search for antichagasic drugs, 14 new 4-(nitroarylidene)-1,2,6-thiadia zin-3,5-dione 1,1-dioxide derivatives were synthesized and tested in vitro against the epimastigote form of Trypanosoma cruzi and some of them showed important antiprotozoan activity. Attempts to synthesize new 4-(nitroarylid ene)-3,5-diamino-1,2,6-thiadiazine 1,1-dioxides were unsuccessful. The anti chagasic properties of nitroarylidene-malononitrile and nitroarylidene-cyan oacetamide derivatives, thus obtained, were also tested. The cytotoxic prop erties against Vero cells of compounds which showed remarkable in vitro ant ichagasic activity were evaluated. All compounds tested exhibited high toxi city percentages at 100 mu g/ml. However, compound 3c showed in vitro antic hagasic and cytotoxic properties such as nifurtimox at the dose of 10 mu g/ ml.