Silica Supported Acids (SiO2-HClO4, SiO2-KHSO4) as Eco-friendly Reusable Catalysts for Bromination of Aromatic and Heteroaromatic Compoundsusing Kbr Under Solvothermal and Solvent-free Conditions

Abstract

Silica supported nanogreenacids like Si-KHSO4, and Si-HClO4are explored as reusable catalysts for bromination of aromatic and hetero aromatic compounds using KBr under solvothermal, and solvent-free conditions. Reaction times reduced from Reacions under conventional solvothermal protocols conditions required (4 – 6) hours, while ultrasonic assisted reactions only (9 – 12) minutes for completion. But, solvent-free microwave assisted reactions required only (1-5) minutes exhibiting striking rate acceleration compared to the solvothermal and ultrasonic assisted protocols All the reaction protocols afforded fairly good yields of brominated products, which are comparable with existing protocols.