Unexpected formation of pyrrolo[1,2-a]quinoxaline derivatives during the multicomponent synthesis of pyrrolo[1,2-a]benzimidazoles
作者:Alina Nicolescu、Calin Deleanu、Emilian Georgescu、Florentina Georgescu、Ana-Maria Iurascu、Sergiu Shova、Petru Filip
DOI:10.1016/j.tetlet.2013.01.036
日期:2013.3
New pyrrolo[1,2-a]benzimidazole and pyrrolo[1,2-a]quinoxaline derivatives are obtained via one-pot, three-component reactions from 1-benzylbenzimidazoles, alpha-bromocarbonyl compounds, and non-symmetrical activated acetylenic dipolarophiles in propylene oxide as both the reaction medium and acid scavenger, at room temperature. When the same reaction is performed in 1,2-epoxybutane at reflux temperature only the pyrrolo[1,2-a]benzimidazole derivative is obtained. (C) 2013 Elsevier Ltd. All rights reserved.