Convenient syntheses of dihydropyrrolo[2′,1′:3,4]pyrazino- and dihydropyrrolo[2′,1′:3,4][1,4]diazepino-[2,1-a]isoindolones

Abstract

Dihydropyrrolo[2′,1′:3,4]pyrazino[2,1-a]isoindolones 10a-10c were obtained in 76-81% yields by the reaction of 2-(1H-pyrrol-1-yl)ethylamine 8 with 2-formylbenzoic acids 9a, 9b or 2-acetylbenzoic acid 9c via N-acyliminium cation aromatic cyclizations. Similarly, dihydropyrrolo[2′,1′:3,4][1,4]diazepino[2,1-a]isoindolones 12a, 12b were prepared in one-pot reactions from 3-(1H-pyrrol-1-yl)propylamine 11 and 2-formylbenzoic acids 9a, 9b. © 2002 Elsevier Science Ltd. All rights reserved.