Recyclization of 4,5-diaroyl-substituted 1H-pyrrole-2,3-diones effected by benzylhydrazine

Spiro heterocyclization of 4,5-diaroyl-2,3-dihydro-1H-pyrrole-2,3-diones with ethyl 3-amino-3-phenylprop-2-enoate

“…We previously described recyclizations of 4,5-diaroyl-1H-pyrrole-2,3-diones in reactions with aromatic amines [1] and substituted hydrazines [2,3], which led to the formation of 1,5-diaryl-5-hydroxy-4-(2-aryl-1-arylamino-2-oxoethylidene)pyrrolidine-2,3-diones and substituted N-aryl-2-(5-aryl-3-aroyl-1H-pyrazol-4-yl)-2-oxoacetamides, respectively. However, there no published data on reactions of 4,5-diaroyl-1H-pyrrole-2,3-diones with 1,3-binucleophiles.…”

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SHORT COMMUNICATIONSWe previously described recyclizations of 4,5-diaroyl-1H-pyrrole-2,3-diones in reactions with aromatic amines [1] and substituted hydrazines [2,3], which led to the formation of 1,5-diaryl-5-hydroxy-4-(2-aryl-1-arylamino-2-oxoethylidene)pyrrolidine-2,3-diones and substituted N-aryl-2-(5-aryl-3-aroyl-1H-pyrazol-4-yl)-2-oxoacetamides, respectively. However, there no published data on reactions of 4,5-diaroyl-1H-pyrrole-2,3-diones with 1,3-binucleophiles.

By heating a solution of equimolar amounts of 4,5-diaroyl-1-(4-methylphenyl)2,3-dihydro-1H-pyrrole-2,3-dione Ia or Ib and ethyl 3-amino-3-phenylprop-2-enoate II in anhydrous benzene under reflux over a period of 2-3 h (the progress of the reaction was monitored by TLC) we obtained ethyl 6-aryl-4-aroyl-3-hydroxy-2-oxo-1-(4-methylphenyl)-8-phenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylates IIIa and IIIb whose structure was confirmed by the X-ray diffraction data for compound IIIa.

Compounds IIIa and IIIb are likely to be formed via initial addition of the β-CH group in enamine II at the C 5 atom of pyrrole-2,3-dione Ia or Ib to give intermediate A which undergoes intramolecular cyclization with participation of the amino group and ketone carbonyl group attached to C 5 in the pyrrole ring.

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Five-membred 2,3-dioxoheterocycles: LXXXI. Reactions of 4,5-bis(methoxycarbonyl)-1H-pyrrole-2,3-diones with N-substituted 3-amino-5,5-dimethyl-2-cyclohex-2-en-1-ones. crystal and molecular structure of methyl 4′-hydroxy-6,6-dimethyl-1,1′-bis(4-methylphenyl)-2,4,5′-trioxo-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-3′-carboxylate

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1-Aryl-4,5-bis(methoxycarbonyl)-1Н-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.It was shown formerly that the direction of the reaction between monocyclic 1Н-pyrrole-2,3-diones with enamines was governed by the structure of the substituents in the pyrroledione ring [2][3][4][5].The reaction of 1-alkyl-5-phenyl-4-ethoxycarbonyl-1Н-pyrrole-2,3-diones with N-aryl-substituted enamines proceeds as a successive addition of the groups of the ortho-СН of aryl substituent and β-СН of the enamine fragment to the С 3 atom of pyrrolediones [2, 3]. 4-Isopropoxalyl-1,5-diphenyl-1Н-pyrrole-2,3-dione reacted with enamine adding the NH and β-СН groups of the enamine fragment to atoms С 2 and С 3 of pyrroledione followed by the cleavage of the pyrroledione ring and by subsequent cyclization [4].

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“…4-Isopropoxalyl-1,5-diphenyl-1Н-pyrrole-2,3-dione reacted with enamine adding the NH and β-СН groups of the enamine fragment to atoms С 2 and С 3 of pyrroledione followed by the cleavage of the pyrroledione ring and by subsequent cyclization [4]. In the reaction of 1-aryl-4-aroyl-5-methoxycarbonyl-1Н-pyrrole-2,3-diones with enamines the process proceeds along three directions.…”

“…It was shown formerly that the direction of the reaction between monocyclic 1Н-pyrrole-2,3-diones with enamines was governed by the structure of the substituents in the pyrroledione ring [2][3][4][5].…”