Synthesis and spectroscopic properties of 1-(acridin-9-yl)-dipyrranes and 1-(acridin-9-yl)-dipyrrins

Abstract

A new process leading to 1-(acridin-9-yl)dipyrranes has been elaborated. The titled skeleton is assembled in a convergent fashion from 5-aryl substituted dipyrranes and acridine via a nucleophilic addition, followed by the oxidation of adducts, which are formed in situ. These products were transformed into respective 1-(acridin-9-yl)dipyrrins via 2,3-dichloro-4,5-dicyano-1,4-benzoquinone mediated oxidation. Spectroscopic studies were conducted which revealed large Stokes shifts in 1-(acridin-9-yl)dipyrranes and led to the conclusion that there is a significant conjugation between both moieties in molecules of 1-(acridin-9-yl)dipyrrins.