A comparative study of the regioselective ring opening of styrene oxide with aniline over several types of mesoporous silica materials

In this study, three different mesoporous silica materials, i.e. rice husk ash, RHA-MCM-41 and commercial silica gel were employed as catalyst to study the styrene oxide ring opening with aniline to form β-amino alcohols. RHA-MCM-41 with a high surface area of 1115 m2 g−1 was prepared from rice husk silica using cetyltrimethylammonium bromide as a structure directing agent via a simple sol–gel method at 80 °C. The TEM image showed a typical MCM-41 structure with the pore size and pore wall thickness of 2.32 and 1.87 nm, respectively. The catalytic activity of these catalysts resulted in a conversion of 95% and a selectivity of 94% for isomer I. Aromatic solvents were found to be more effective compared to non aromatic and polar solvents for the reaction.

MCM-41 prepared from rice husk ash was used as a catalyst for the synthesis of β-amino alcohols at 70 °C with toluene as solvent. Higher selectivity of 94.0% of 2-phenylamino-2-phenylethanol (isomer I) and 5.3% of 2-phenylamino-1-phenylethanol (isomer II) was produced from aminolysis of styrene oxide.Figure optionsDownload as PowerPoint slideHighlights
► RHA-MCM-41 was synthesized from rice husk ash (RHA) via simple sol–gel technique.
► RHA-MCM-41 exhibited ordered mesoporous straight-channels with SBET of 1115 m2 g−1.
► The catalyst showed high activity in aminolysis reaction with 95.4% conversion.