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The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and ninhydrin afforded functionalized spiro[indene-2,4'-pyrrolo[3,4- b]pyridines] and spiro[acenaphthylene-1,4'-pyrrolo[3,4- b]pyridines] in good yields. The similar reaction of phenanthrene-9,10-dione resulted in the formation of the unexpected complex phenanthro[9',10':4,5]furo[2,3- c]pyrrolo[3,4- b]pyrroles in satisfactory yields. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]