Green Synthesis of 1<i>H</i>-Benzo[d]Imidazol-2-yl-4-(Aryldiazenyl)Phenol and Bis Benzo[d]Imidazoles Using Fe₃O₄@Silicapropyl@Vanillin/Thiamin Nanoparticles

Fe3O4@Silicapropyl@Vanillin/Thiamin nanoparticles were synthesized by a simple immobilization method using cheap and natural materials. The nanocatalyst was analyzed XRD, FT-IR, FE-SEM, TEM, VSM TGA techniques applied as new, effective magnetically recoverable solid acid for the synthesis of azo-linked benzo[d]imidazoles or bis via reaction corresponding aldehydes 1,2-diaminobenzene in water green solvent. At end reaction, catalyst could be separated filtration mixture presence an external magnet recycled 7 consecutive runs, without significant decrease efficiency. This avenue has advantages such simplicity operation, aspect avoiding toxic conventional catalysts solvents.