Four component synthesis of pyrrolo[3,2-c]pyridin-4-one derivatives

Abstract A direct and metal-free access toward poly-substituted pyrrolo[3,2-c]pyridin-4-one and its analogues have been established through a simple four-component, two-step reaction of 4-hydroxy-6-methyl-2H-pyran-2-one, two amine molecules, and β-nitrostyrenes. The reaction allows the formation of five different C-N, C-C bonds by the multiple bond cleavage only using acetic acid as catalyst and solvent. The advantages of broad substrate scope, efficient and metal-free reaction conditions, inexpensive and readily available starting materials as well as simple one-pot two-step operation, make the strategy highly attractive. This transformation in acetic acid resulted in the rapid establishment of functional bioactive poly-substituted pyrrolo[3,2-c]pyridin-4-one derivatives.