Nanocomposite based on sulfonated-melamine-formaldehyde resin and Fe3O4 as a highly efficient catalyst for the synthesis of 1,4-dihydropyrano[2,3-c] pyrazole derivatives

Current research work presents a high efficiency polymer based nanocomposite as catalyst for using in the synthesis of organic compounds. Among the polymer-based catalyst, sulfonated-melamine–formaldehyde resin, which has excellent physical and chemical stability, is widely used in chemical transformations. Thus, a novel magnetic sulfonated melamine–formaldehyde resin (MSMF) catalyst was successfully prepared from a mixture of sulfonated melamine-formaldehyde and Fe3O4 nanoparticles. The resulted MSMF was characterized by FTIR, CHNSO, SEM, VSM and TGA analysis. The catalytic activity of MSMF was examinedin the preparation of 1,4-dihydropyrano[2,3-c] pyrazole derivatives. 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized via one‐pot three‐ component condensation of variousaromatic aldehydes with malononitrile and 3-methyle -1-phenyl-5-pyrazolone in excellentyields in the presence of MSMF as a highly efficient heterogeneous catalyst. Results showedthe MSMF is an excellent catalyst for green chemical processes owing to its high catalyticactivity, stability and reusability.