Diimidazo[4,5-b:4′,5′-e]pyridine: synthesis and nucleophilic aromatic substitution reaction

1,7-Dihydrodiimidazo[4,5-b:4′,5′-e]pyridine obtained by reductive heterocyclization was N-arylated with 4-fluoronitrobenzene to form two regioisomers in 7 : 3 ratio. This N-arylation is considered as a model reaction for the polymer synthesis.