Nano-Fe3O4@ZrO2-SO3H as highly efficient recyclable catalyst for the green synthesis of fluoroquinolones in ordinary or magnetized water

Core–shell zirconia-coated magnetite nanoparticle bearing sulfonic acid groups (nano-Fe3O4@ZrO2-H3PO4) have been prepared and used as an efficient acid catalyst in the synthesis of fluoroquinolons 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. The reaction was carried out in the ordinary or magnetized water as a solvent. In the final outcomes, the nano-Fe3O4@ZrO2-SO3H showed good catalytic performance in the both forms of water. However, the magnetized water showed better results. Therefore, this new procedure provides prompt achievement to the appropriate products with acceptable yields in water as a green solvent at reflux situations with an easy work‐up process. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity.