Formation of Novel Pyrido[3′,2′:4,5]Thieno [2,3-e][1,2,4]Triazolo[4,3-c] Pyrimidines and their Acyclic C-Nucleosides Analogues: Synthesis of 3-(Alditol-1-yl)Pyridothienotriazolopyrimidines

A series of the hydrazones were prepared by the reaction of 4-hydrazino-7,9-dimethylpyrido[3′,2′:4,5]thieno [2,3-d]pyrimidine (1) with monosaccharides, and their acetylation was studied. The oxidative cyclisation of the hydrazones 3a–c gave 3-(Alditol-1-yl)-pyridothienotriazolopyrimidenes 5a–c, whose acetylation was carried out. Also, oxidative cyclisation of arylidenes 7a,b gave the pyridothienotriazolopyrimidines 8a,b.