Abstract A new synthetic route to 6-substituted-imidazo [4, 5-c] pyridin-2-ons from 4- aminopyridine has been investigated. 4-Aminopyridine protected as alkyl carbamates were nitrated with dinitrogen pentoxide to the corresponding methyl, i-propyl and t-butyl 3- nitropyridin-4-yl carbamates (5a-c) in 51-63% yields. Attempts to substitute these in the 6- position by the ONSH and the VNS techniques succeeded with butyl-amine and the t-butyl ...
