The Ugi reaction in the synthesis of pyrrolo[3,4-c]pyridine derivatives

For the first time, a four-center three-component Ugi reaction has been developed involving isonitriles, amines and bifunctional pyridine derivatives containing carbonyl and carboxyl groups (U-4C-3CR-Py). A series of fourteen new 1-oxo-2,3-dihydro-1H-pyrrolo[3,4-c]pyridine-3-carboxamides was synthesized using the proposed methodology. It was established that the reaction proceeds through the formation of an intermediate 3-(arylamino)furopyridinone, which was successfully isolated and reacted with an isonitrile to form the target products. The developed method is characterized by mild conditions, the absence of a catalyst and broad substrate scope with respect to both the amine and isonitrile components.