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1-Aryl-4,5-bis(methoxycarbonyl)-1H-pyrrole-2,3-diones react with ethyl 3-(benzylamino)but-2-enoate and ethyl 3-(benzylamino)-3-phenylacrylate giving 4-methyl 9-ethyl 1-aryl-7-benzyl-3-hydroxy-8-methyl- and 4-methyl 9-ethyl 1-aryl-7-benzyl-3-hydroxy-8-phenyl-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-4,9-dicarboxylates.

Dimethyl 1-aryl(benzyl)-4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates reacted with phenylhydrazine and benzylhydrazine to give dimethyl 1-aryl(benzyl)-5-[(aryl or benzyl)carbamoyl]-1H-pyrazole-3,4-dicarboxylates.

1-Aryl-4,5-bis(methoxycarbonyl)-1H-pyrrole-2,3-diones react with N-substituted 3-amino-5,5-dimethylcyclohex-2-en-1-ones affording methyl 1,1′-diaryl-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-3′-carboxylates whose structure was proved by XRD analysis.

The first example of a [3 + 3]-nucleophilic addition of acyclic enamines to monocyclic pyrrole-2,3-diones (I) is described, furnishing 2,6-diazabicyclo[3.2.1]octane derivatives (III), which are otherwise difficulty to access .

Reactions of dialkyl 4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates with enamines were reported previously. By reaction of 1-(4-methylphenyl)-4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylate (I) with an equimolar amount of 3-arylamino-5,5-dimethylcyclohex-2-en-1-one IIa or IIb in boiling toluene (reaction time 3–4 h) we obtained methyl 1-aryl-1′-(4methylphenyl)-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-3′carboxylates IIIa and IIIb. The spectral parameters of compounds IIIa and IIIb turned out to be quite similar to those of model 3′-benzoyl-1-cyclohexyl-4′-hydroxy6,6-dimethyl-1′-phenyl-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-2,4,5′-trione whose structure was proved by X-ray analysis [1].

Reactions of dialkyl 4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates with enamines were reported previously. By reaction of 1-(4-methylphenyl)-4,5-dioxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylate (I) with an equimolar amount of 3-arylamino-5,5-dimethylcyclohex-2-en-1-one IIa or IIb in boiling toluene (reaction time 3–4 h) we obtained methyl 1-aryl-1′-(4methylphenyl)-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-3′carboxylates IIIa and IIIb. The spectral parameters of compounds IIIa and IIIb turned out to be quite similar to those of model 3′-benzoyl-1-cyclohexyl-4′-hydroxy6,6-dimethyl-1′-phenyl-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-2,4,5′-trione whose structure was proved by X-ray analysis [1].