A CONTINUOUS PROCESS TOWARDS THE SYNTHESIS OF QUINOLONES

Abstract The development of quinolones is described from the first quinolone to the latest fluoroquinolones. Quinolones have generated considerable interest since their discovery because of their antibacterial capabilities. Analogs incorporating the 4-quinolone ring system comprise a largely expanding group of synthetic compounds. The development of antibacterial resistance has created the need for an efficient synthesis of quinolones that can be easily adapted toward the assembly of quinolone based antibacterial drugs. There are several reported approaches to the 4-quinolone ring system. Many of these methods use expensive starting materials, require the removal of high boiling solvents, or use high temperature conditions (\u3e200°C) for the final cyclization. Our synthesis of 4-quinolones was achieved via continuous flow chemistry using inexpensive starting materials in easily removable solvents, and under mild conditions. Flow chemistry is the use of technology that allows a continuous flow of reagents to be introduced at various points along a process stream, enabling interaction under highly controlled conditions. By employing this technology we achieved a more rapidly scalable synthesis of 4-quinolones, offering safer reacting conditions and highly reproducible results