4-Quinolone

4-Quinolone is an organic compound derived from quinoline. It and 2-quinolone are the two most important parent quinolones. 4-Quinolone exists in equilibrium with a minor tautomer, 4-hydroxyquinoline. Aside from pedagogical interest, 4-quinolone is of little intrinsic value but its derivatives, the 4-quinolone antibiotics, represent a large class of important drugs.

Synthesis

The chemical synthesis of quinolones often involves ring-closing reactions. Such reactions often install a hydroxyl group on the carbon across from the ring nitrogen. An example of such a synthesis is the Camps cyclization, which, depending on starting materials and reaction conditions, can give both 2-hydroxyquinolines and 4-hydroxyquinolines as shown. The hydroxyquinolines tautomerize to the quinolones.