New methodology for acridine synthesis using a rhodium-catalyzed benzannulation

A new methodology for the synthesis of acridine derivatives is disclosed. The starting materials are commercially available quinolines, which can be converted, via five high efficient steps, in a key quinoline intermediate substituted with a TBS-protected-enol–ether and an internal alkyne. The key and last step is a rhodium-catalyzed benzannulation of the quinoline intermediate yielding the desired poly-substituted acridines derivatives.