A one-pot, three-component synthesis of novel pyrroloacridinones from a set of alkoxy arenes and 2,6-dialkylphenols, isobutyric aldehyde, and 2-aminobenzonitrile is described. We have demonstrated the efficacy of the combination of intramolecular electrophilic ipso dearomatization of suitable aromatic compounds leading to spiro-substituted cyclohexa-2,5-dienones and intramolecular aza-Michael addition for the preparation of complex azaheterocyclic systems.Dearomatization of para-substituted phenols and alkoxy arenes forming 4,4-disubstituted-cyclohexa-2,5-dienones, coupled with intramolecular 1,4-conjugate addition is an efficient and convenient synthetic approach to different carbo-and heterocyclic-fused ring systems with a cyclohexenone moiety, including bioactive compounds and structural units found in natural products. 1-3 Combination of intramolecular ipso dearomatization of arenes leading to spiro-substituted cyclohexa-2,5-dienones and intramolecular 1,4-conjugate addition is of particular interest because this synthetic transformation provides a facile route to the construction of highly functionalized fused spiro tricyclic or tetracyclic compounds with a quaternary carbon at the ring-fused position. 4 Furthermore, in some cases this process leads to the formation of structures bearing an asymmetric quaternary carbon center. 4d-g Despite great potential of this synthetic approach to the construction of complex heterocyclic systems, its use is currently limited. Here, we demonstrated an efficient route to novel pyrroloacridinones via a one-pot, three-component protocol via intramolecular ipso dearomatization-intramolecular azaMichael addition sequence. We have recently developed a simple and efficient one-pot protocol for the construction of 2-azaspiro[4.5]deca-1,6,9-trien-8-ones via a threecomponent condensation of a set of alkoxy arenes and alkylphenols with isobutyric aldehyde and nitrile in the presence of concentrated sulfuric acid (Scheme 1). 5 This method is based on the intramolecular electrophilic ipso dearomatization of suitable aromatic compounds. Since the 2-azaspiro[4.5]deca-1,6,9-trien-8-ones could be suitable substrates for the 1,4-conjugate addition, we asked ourselves whether ipso intramolecular dearomatizationintramolecular aza-Michael addition sequence would be observed if nitrile containing an additional amino group were used. Scheme 1 Formation of 2-azaspiro[4.5]deca-1,6,9-trien-8-ones via a three-component condensation To estimate a possibility of this transformation, we investigated the condensation of various alkoxy arenes and 2,6-dialkylphenols 1 with isobutyric aldehyde 2 and 2-aminobenzonitrile 3. Our investigation started with the reaction of 1-methoxynaphthalene (1a) with isobutyric aldehyde (2) and 2-aminobenzonitrile (3) in the presence of concentrated sulfuric acid.We were pleased to find that the desired intramolecular ipso dearomatization-intramolecular aza-Michael addition domino sequence had occurred, and novel tetrahydrobenzo[a]pyrrolo[2,3-m]acridin-5(6H)-one (5a) was is...

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Reactions of available 1-alkyl-3,4-dihydroisoquinolines with 4-(2,2,2-trifluoroacetyl)-, 4-acetyl-or 4-(ethoxy-methylene)-2-aryloxazol-5(4H)-ones were studied. A series of new 3-amino-6,7dihydro-4H-pyrido[2,1-a]isoquinolin-4-one derivatives was synthesized. The intermediates formed as a result of the addition of azlactone to 1-methyl-3,4-dihydroisoquinoline were isolated. The effect of the nature of the substituents, as well as the reaction conditions on the yield and structure of the title products was revealed.

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