Tetrahydropyrido[3,4-<i>b</i>]pyrazine Scaffolds from Pentafluoropyridine

Representative polyfunctional tetrahydropyrido[3,4-b]pyrazine scaffolds have been synthesized very
readily by a one-pot annelation reaction of pentafluoropyridine with appropriate diamines. The
trifluorinated pyridopyrazine products react sequentially with various nucleophiles to give
polysubstituted tetrahydropyridopyrazines, demonstrating the potential of the polyfluorinated ring
fused pyridine system as a scaffold for the synthesis of previously inaccessible polysubstituted
pyridopyrazine derivatives. This general approach has special relevance to the development of new
chemical entities for the life science industries and particularly in the drug discovery arena, in
which low molecular weight, polyfunctional heterocyclic derivatives are playing an increasingly
important role.