Synthesis of Benzo[c][1,8]phenanthrolin-6-one Through Cyclization of N-(Isoquinol-5-yl)-2-bromo-benzamideDerivatives. -The access to benzophenanthrolinone (VII) involves the key cyclization of isoquinolyl dimethoxybenzamide (III) either using a benzyne intermediate cyclization or a palladium-assisted intramolecular biaryl coupling reaction. The first cyclization attempt yields only traces of target compounds (VII) along with the unexpected compound (IV), which is the result of an internal Diels-Alder reaction between the benzyne intermediate and the isoquinoline ring system. In the course of an alternate preparation of (III) using the carbodiimide EDC, the bisbenzamide (VIII) is obtained as an already protected precursor to give under the previous palladium-assisted cyclization conditions the target (VII) in a much improved yield. -(PRADO, S.; MICHEL, S.; TILLEQUIN*, F.; KOCH, M.; J. Heterocycl.