3-Aryl β-carbolin-1-ones as a new class of potent inhibitors of tumor cell proliferation: Synthesis and biological evaluation

A novel three-step synthesis of 3-aryl β-carbolin-1-ones from non-indole starting materials has been developed. The two nitrogen atoms in β-carbolin-1-one were introduced efficiently by Michael addition of ethyl acetamidocyanoacetate to chalcone. The desired pyridone and indole rings were assembled by an intramolecular ketone-nitrile annulation mediated by aqueous HCl-HOAc and a Cu(i)-catalyzed intramolecular N-arylation of the amide, respectively. The target compounds were found to possess significant activity against tumor cell proliferaton.