Application of ZrO2–SO3H as highly efficient recyclable nanocatalyst for the green synthesis of fluoroquinolones as potential antibacterial

Various antibacterial fluoroquinolone compounds were prepared by the direct amination of 7-halo-6- fluoroquinolone-3-carboxylic acids with variety of piperazine derivatives and (4aR,7aR)-octahydro-1H-pyrrolo[3,4-b] pyridine using Zirconia Sulfuric Acid (ZrSA) nanoparticle, as a catalyst in refluxing water. The results showed that ZrSA exhibited high catalytic activity towards the synthesis of fluoroquinolone derivatives, with the desired products being formed in high yields. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity. Overall, this new catalytic method for the synthesis of fluoroquinolone derivatives provides rapid access to the desired compounds in refluxing water following a simple work‐up procedure, and avoids the use of harmful organic solvents. This method, therefore, represents a significant improvement over the methods currently available for the synthesis of fluoroquinolone derivatives.