4,5-Bis(dimethylamino)quinolines: Proton Sponge versus Azine Behavior

Abstract

Two first representatives, <b>5</b> and <b>6</b>, of the still unknown 4,5-bis(dimethylamino)quinoline have been synthesized and studied. While the former, being protonated either at the peri-NMe₂ groups or at the ring nitrogen, has been shown to display properties of both a proton sponge and azine, its counterpart <b>6</b> behaves exclusively as azine giving only a quinolinium salt