Non-natural nucleosides based on 1,2,4-triazolo[5,1-c][1,2,4]triazin-4(6H)- ones

Abstract

Two regioselective methods for the synthesis of nucleosides in the series of 3-phenyl- and 3- ethoxycarbonyl-1,2,4-triazolo[5,1-c][1,2,4]triazin-4-ones were developed. The first route involves a Vorbrüggen glycosylation reaction. The second one is based on condensation of 1,2,4- triazolo[5,1-c][1,2, 4]triazin-4-one sodium salts with protected 1-bromo-sugar derivatives.