Facile, regioselective syntheses of N-alkylated 2,3-diaminopyridines and imidazo(4,5-b)pyridines

2,3-diaminopyridines offer a route for efficient regioselective synthesis of N-alkylated 2,3-diaminopyridines with substituents at 2 and 3 positions and imidazo (4,5-b) pyridines, which are cyclized products resulting from the reactivity of amino groups at the 2 and 3 positions. The nature of reaction conditions induce the formation of N-1 or N-3-alkylated imidazopyridines from the intermediate 2-formamido-3-aminopyridine.