Representative polyfunctional tetrahydropyrido[3,4-
b]pyrazine scaffolds have been synthesized veryreadily by a one-pot annelation reaction of pentafluoropyridine with appropriate diamines. Thetrifluorinated pyridopyrazine products react sequentially with various nucleophiles to givepolysubstituted tetrahydropyridopyrazines, demonstrating the potential of the polyfluorinated ringfused pyridine system as a scaffold for the synthesis of previously inaccessible polysubstitutedpyridopyrazine derivatives. This general approach has special relevance to the development of newchemical entities for the life science industries and particularly in the drug discovery arena, inwhich low molecular weight, polyfunctional heterocyclic derivatives are playing an increasinglyimportant role.
