Selective Synthesis of 1,2‐Diarylpyrrolo[3,4‐ b ]pyridine‐5,7‐diones via Cyclization Reaction of β ‐Enamino Imides with Cinnamaldehydes

The novel 1,2‐diaryl substituted pyrrolo[3,4‐ b ]pyridine‐5,7‐diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3‐arylamino‐1‐methyl‐1 H ‐pyrrole‐2,5‐diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2‐diaryl and 1,4‐diaryl substituted pyrrolo[3,4‐ b ]pyridine‐5,7‐diones in comparable yields.