A straightforward strategy for the fabrication of a new sulfonic acid modified covalent organic framework supported on Fe3O4 nanoparticles namely Fe3O4@COF–SO3H was introduced. Combining the important advantages of high specific surface area and porosity, chemical and thermal stability, magnetic responsibility and abundant sulfonic acid sites, make Fe3O4@COF–SO3H a robust and unique catalyst for the preparation of triazolo quinazolinones and 4H pyrimidobenzothiazoles. In addition, Fe3O4@COF–SO3H has convenient magnetic responsibility which is easily separated from the reaction mixture. These factors, in turn, led to desired molecules under mild and green conditions.
