Synthetic Access to 2-Amido-5-aryl-8-methoxy-triazolopyridine and 2-Amido-5-morpholino-8-methoxy-triazolopyridine Derivatives as Potential Inhibitors of the Adenosine Receptor Subtypes

ABSTRACT Two versatile and complementary synthetic strategies towards 2-amido-5-aryl-8-methoxy-triazolopyridine derivatives and 2-amido-5-morpholino-8-methoxy-triazolopyridine derivatives in five steps are presented. The key step in each synthetic route can be constituted as the formation of the respective triazolopyridine derivative precursors in 78% and 57% yield, respectively, through an intermediately formed 4H-[1,2,4]oxadiazol-5-one. The final Suzuki coupling/amidation allowed the straightforward access to the desired triazolopyridine derivatives which have not been described previously. Notably, these triazolopyridine-scaffold bears three vectors of diversity which offer maximum flexibility in design and combinatorial synthesis of molecules with a potentially useful inhibitory activity towards adenosine receptor subtypes.