Synthesis of 5-aza-7-deazaguanine nucleoside derivatives as potential anti-flavivirus agents

Coupling suitable sugars (D- or L-ribofuranose, 2' or 3-deoxysugar, branched sugars) with 2-aminoimidazo1,2-a]-s-triazin-4-one was carried out using the different reaction conditions: 1) condensation in the presence of sodium hydride; or 2) condensation using Vorbrüggen's methods. The 5-aza- 7-deazaguanine nucleoside analogues obtained were evaluated in cell culture experiments for the inhibition of the replication of a number of RNA viruses, including BVDV, YFV, and WNV.