An Efficient and Green Approach for the Esterification of Aromatic Acids with Various Alcohols over H₃PO₄/TiO₂-ZrO₂

摘要

TiO2-ZrO2 was prepared with surfactant through a sol-gel method. Catalysts containing 5 - 35% H3PO4 were prepared using these oxides. Subsequently the catalytic performance of prepared catalysts was determined for liquid phase esterification of aromatic acids. H3PO4/TiO2-ZrO2 has been used as catalyst to synthesize various novel esters by esterification of some aromatic acids with aliphatic alcohols (2-propanol, 1-butanol, iso butanol, 3-pentanol, 1-hexanol, heptanol, cyclo heptanol, octanol and decanol). Under optimized conditions, maximum yields and selectivity (100%) to the corresponding ester, was obtained by using 25 wt % H3PO4/TiO2-ZrO2 as catalyst. The Catalyst can be easily recycled after reaction and can be reused without any significant loss of activity/selectivity performance. No by-product formation, high yields, short reaction times, mild reaction conditions, operational simplicity with reusability of the catalyst are the salient features of the present synthetic protocol. The reaction was carried out under solvent-free condition.