Preparation of 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones via base-assisted cyclization of 3-cyanoketones

Abstract

The highly efficient oxidative cyclization of 1,3-diarylsubstituted 3-cyanoketones yielded 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones.

One-Pot Synthesis of Polynuclear Indole Derivatives by Friedel–Crafts Alkylation of γ-Hydroxybutyrolactams

“…Moreover, upon the evaluation of a mouse model, some of those indole hydroxamic acids were able to reduce melanoma xenotransplant growth [ 24 ]. Encouraged by such results, we turned our attention to 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-one 5 , that was earlier found [ 25 ] to undergo a Friedel–Crafts reaction with anilines and phenols. We speculated that the interaction of 5 with indoles 6 would lead to previously unknown 4-(indol-3-yl)butyramide 7 , which are, basically, cyclic analogs of the above indole acetamides/hydroxamic acids ( Scheme 1 ).…”

“…Keeping that in mind, we initially attempted to reproduce the original conditions of our work [ 25 ] using microwave heating for the xylene, only to obtain the desired product at a disappointing 11% yield ( Table 1 , entry 1). Next, we tried different acidic additives with or without solvents as activators (entries 2–7), but such a treatment produced no effect.…”

Oxidative Cyclization of 4-(2-Aminophenyl)-4-oxo-2-phenylbutanenitriles into 2-(3-Oxoindolin-2-ylidene)acetonitriles

“…The acidic α-CH bond next to cyano function in this structure could also be deprotonated with KOH, followed by the elimination of dimethylsulfide and water to afford cyanochalcone 14 . In our recent report, we demonstrated similar oxidations of cyanoketones lacking ortho -aniline functionality …”

“…In our recent report, we demonstrated similar oxidations of cyanoketones lacking ortho -aniline functionality. 20 …”

“…In our recent report, we demonstrated similar oxidations of cyanoketones lacking ortho-aniline functionality. 20 In the presence of such ortho-amino group, subsequent nucleophilic 5-exo-trig cyclization would render indoline-3-one 15, which could then be deprotonated at the α-CH bond of the cyano group. The resulting cyclic enolate 16 could again react with DMSO providing dimethylvinylsulfanol 17.…”