Abstract
A novel fused system with three or four fused rings—pyridazino[3′,4′:5,6][1,2,4]triazino[4,3-
][1,2,4,5]tetrazine and pyridazino[3′,4′:5,6][1,2,4]triazino[3,4-
]pyrimido[4,5-
][1,3,4]thiadiazine was obtained from the starting materials 4(6
)-amino-3-hydrazino-7-(2-thienyl)pyridazino[3,4-
][1,2,4]-triazine
and 9-amino-3-(2-thienyl)-2
,8
-pyridazino[3′,4′:5,6][1,2,4]triazino[3,4-
][1,3,4]thiadiazine-8-carbonitrile
. Each of the starting compounds was subjected to a number of cyclization reactions to obtain a series of new heterocyclic fused systems,
⁻
and
⁻
, via bifunctional reagents. Some of the synthesized compounds were screened against three cell lines including HepG2, HCT-116 and MCF-7 to discover their anticancer activity. The synthesized compounds were characterized depending on their elemental analyses and spectral data.