Synthesis of heterobicyclic nitrogen systems bearing the 1,2,4-triazine moiety as anti-HIV and anticancer drugs, part III

Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b] [1,3,4] thiadiazolones/thiadiazinones 4-15 and the related compounds 16-21 have been synthesized from treatment of 4-amino-3-mercapto-6-substituted-1,2,4-triazin-5-ones 1 with bifunctional oxygen and halogen compounds via heterocyclization reactions. Structures of the products have been deduced from their elemental analysis and spectral data. Significant anti-HIV and anticancer activities were observed in vitro for some members of the series, compounds 1e, 4e, 4f, 5, 6 and 16 showing a significant activity in Leukemia, Lung, Breast and CNS anticancer evaluation.