New Cyclization Reactions of 3-Dialkylamino-4-aminopyridines under Conditions of Nitration

Treatment of 3-dialkylamino-4-aminopyridines (1) with nitric and sulfuric acids affords imidazo-[4,5-c] pyridine derivatives (2, 3 and 4) and 1,2,3- triazolo [4,5-c] pyridine 2-oxides (5) by cyclization reaction of the corresponding 4-nitroaminopyridines