In this study, a rationally tailored deep eutectic solvent supported on Fe3O4@SiO2 (catalyst II) was applied as a robust catalyst for the preparation of pyranopyrazoles and pyrazolopyridines under mild reaction conditions. Furthermore, the chemical and physical features of catalyst II were detailed by using several characteristic methods including FT-IR, thermogravimetric and derivative thermogravimetry (TGA/DTG), X-ray diffraction (XRD), energy-dispersive X-ray (EDS), elemental mapping, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and vibrating-sample magnetometer (VSM). High yields of pyranopyrazole (78–95 %) and pyrazolopyridine derivatives (81–94 %) were achieved by employing 10 mg of catalyst II under solvent-free conditions. Additionally, catalyst II was recovered and reused up to five times while only a slight decrease in the performance of the catalyst was observed (12 % decrease in yield of product).
