Synthesis of new sulfur-linked 1,2,4-triazolothienopyrimidine and 1,2,4-triazolopyrazolopyrimidine derivatives containing fused heterocyclic pyrimidines

A series of novel bis‐heterocyclic compounds 12, 13, 14, 15, 16, 17, 18, 19, 20 were synthesized by integrating fused heterocyclic pyrimidines, such as thienopyrimidine and pyrazolopyrimidine into the scaffold of thienotriazolo‐ pyrimidines, and pyrazolotriazolopyrimidines through a sulfur‐linkage. J. Heterocyclic Chem., (2010).