Synthesis of chromenpyrimidine[2,4] dione derivatives using M-MSN/COF/Sb(III) as a magnetic and highly efficient nanocatalyst under green conditions

In this study, chromenpyrimidine [2,4]-dione derivatives were synthesized from the reaction of aryl aldehydes, 4-hydroxycoumarin and 6-aminouracil in H 2 O/EtOH (2:1) solvent at room temperature, using a novel magnetic nanocatalyst containing immobilized Sb(III) on nitrogen-riche covalent organic framework (COF) anchored on magnetic mesoporous silica nanoparticles (M-MSN/COF/Sb(III)). The magnetically recoverable nano catalyst was completely analyzed using Raman spectroscopy, Fourier- transform-infrared spectrophotometry (FT-IR), X-ray diffraction (XRD), Field-emmision scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDX), Thermogravimetric analysis (TGA), Vibrating-sample magnetometry (VSM) and Brunauer-Emmett-Teller analysis (BET). The developed catalytic system offers several advantages such as simple reaction setup, mild reaction conditions, high catalytic activity, easy separation from the reaction with an external magnetic field and good reusability. The target products were obtained in high to excellent yields and characterized by FT-IR, 1 H NMR, 13 C NMR, and Mass spectroscopy.