A new route for the synthesis of 4-amino-5-fluoro-7-(2'-deoxy-2'-fluoro-2'-C-methyl-β-D-ribofuranosyl)-1H-pyrrolo[2,3-d]pyrimidine

Design, synthesis, and biological evaluation of novel 2'-deoxy-2'-fluoro-2'-C-methyl 8-azanebularine derivatives as potent anti-HBV agents

Hepatitis B virus (HBV) is a global health problem requiring more efficient and better tolerated anti-HBV agent. In this paper, a series of novel 2'-deoxy-2'-fluoro-2'-C-methyl-β-d-arabinofuranosyl 8-azanebularine analogues (1 and 2a) and N⁴-substituted 8-azaadenosine derivatives (2b-g) were designed, synthesized and screened for in vitro anti-HBV activity. Two concise and practical synthetic routes were developed toward the structural motif construction of 2'-deoxy-2'-fluoro-2'-C-methyl-β-d-arabinofuranosyl 8-azainosine from the ribonolactone 3 under mild conditions. The in vitro anti-HBV screening results showed that these 8-azanebularine analogues had a significant inhibitory effect on the expression of HBV antigens and HBV DNA at a concentration of 20 μM. Among them, halogen-substituted 8-azaadenosine derivative 2g displayed activities comparable to that of 3TC. In particular, 2g retained excellent activity against lamivudine-resistant HBV mutants.

The first example of palladium-catalyzed cascade amidine arylation–intramolecular ester amidation for the synthesis of hypoxanthines: application to the synthesis of 8-azanebularine analogues

A synthetic route toward 8-azanebularines has been developed by involving a cycloaddition and a cascade amidine arylation–intramolecular ester amidation reaction.