Aim and Objective: The importance of Chromeno[4,3-b]pyridines in bioactive
compounds, highlighted the ongoing research on developing novel methods for the construction of
this heterocyclic scaffold. Regarding the advantageous features of multi-component reactions in
organic synthesis, we will try to synthesize pyridocoumarins through this method.
Materials and Methods: Chromeno[4,3-b]pyridines were conveniently prepared from a threecomponent
condensation reaction between 4-hydroxy coumarin, ammonia and ethyl 2,4-dioxo-4-
arylbutanoates in refluxing n-propanol. The synthesized compounds were characterized by NMR, IR
and Mass spectroscopy.
Results: The reaction proceeded through an in situ formed 4-amino coumarin, affording eight new
target compounds in good yields.
Conclusion: This method introduce a novel approach to ethyl 4-aryl-5-oxo-5H-chromeno[4,3-
b]pyridine-2-carboxylate derivatives and allow organic chemists to prepare 4-aminocoumarin in