Synthesis of Phenyl Esters Using SiO2–SO3H Catalyst in Conventional Heating and Microwave-Irradiated Esterification Processes

A SiO 2 –SO 3 H amorphous catalyst containing a small surface area of 115.0 m 2 g −1 and 1.32 mmol H + /g was prepared from fine construction sand and sodium carbonate and sulfonated with H 2 SO 4 . In a 10% (w/w) basis, it is very efficient for catalyzing the esterification of carboxylic acids with phenol. The reaction processes were performed using conventional heating and under microwave irradiation. The yields were higher in the microwave-irradiated esterification. The catalyst could be used for three esterification sequences in both processes.