Base/DMSO-Promoted Synthesis of Benzo[4,5]imidazo[2,1-a]isoquinolines via C-C Bond Formation

In this study, a synthetic method to access benzo[4,5]imidazo[2,1-a]isoquinolines is developed by the reaction of 2-(2-bromoaryl)benzimidazoles with 1,3-diketones under basic conditions. A reaction pathway involving the initial formation of a C-C coupled intermediate by nucleophilic aromatic substitution and subsequent deacylative cyclocondensation is proposed for this process.