Aromatic ring functionalization of benzolactam derivatives: new potent dopamine D3 receptor ligands

Since the discovery of the dopamine D(3) receptor, an intensive effort has been directed toward the development of potent and selective ligands in order to elucidate the function and potential therapeutic advantages of targeting D(3) receptors. As a part of our efforts, a novel series of substituted benzolactams derivatives was synthesized mostly through palladium-catalyzed reactions. Their affinities on D(1)-D(4) receptors were evaluated and the data led us to highly potent D(3) ligands, some of them highly selective for D(3) receptor, compared to the related Dopamine Receptor subtypes. Functional D(3) activity assays of the most relevant compounds have been carried out revealing antagonist as well as partial agonist activity.