Synthesis of Unsymmetrical Ethers Catalysed by Polyvinyl Sulfuric Acid & PVSA / Nano RH SiO2 as a Novel Solid Acid Nanocomposite

Abstract

The methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing of<br />polyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability of<br />the solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetrical<br />ethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid is<br />an appropriate catalytic agent for these condensation reactions. The silica was also extracted from<br />low-cost rice husk and the amorphous silica gel nanoparticles were prepared with sol- gel method.<br />The polyvinyl sulfuric acid was supported on nano rice husk silica. Then the catalytic effect of this<br />system was investigated for synthesis of unsymmetrical ethers which consisted of a combination of<br />high acidic power for this solid acid and high- surface area of nanoparticles. Results show that totally<br />catalytic effect of polyvinyl sulfuric acid supported on nano silica is more suitable than polyvinyl<br />sulfuric acid. The reason for this is in its ability to produce the end products in shorter reaction times<br />while having high isolated yields.