Catalyst-Free Cascade Annulation of Enaminones and Aryl Diazonium Tetrafluoroboronates for Cinnoline Synthesis and the Anti-Inflammatory Activity Study.

A simple and concise method for the synthesis of cinnolines has been developed by the reactions of readily available enaminones and aryl diazonium tetrafluoroboronates. The reactions run efficiently to provide cinnolines with broad diversity in the substructure by heating in dimethyl sulfoxide without using any catalyst or additive. In addition, the primary investigation of the anti-inflammatory activity of these products leads to the observation of p -chlorobenzoyl ( 3f ) and p -nitrobenzoyl ( 3j ) cinnolines as attractive anti-inflammatory compounds in vitro.