Benzo[c][2,7]naphthyridine

Total Synthesis of the Marine Pyridoacridine Alkaloid Demethyldeoxyamphimedine

“…Direct metalation at C-4 of ethyl nicotinate using TMPMgCl·BF 3 ·LiCl, and subsequent transmetalation with ZnCl 2 to 6 , followed by palladium-catalyzed Negishi cross-coupling reaction with 2-iodoaniline led to a biaryl, which underwent lactamization at room temperature to give tricyclic product 7 in 50% yield. This approach is more efficient than previous multistep syntheses . The spectroscopic data of 7 were in full agreement with those reported previously, thus confirming the high C-4 regioselectivity of the initial metalation step.…”