Synthesis of acetyl salicylic acid over WO3/ZrO2 solid superacid catalyst

Solid superacid WO3/ZrO2 was prepared by co-precipitation of an aqueous zirconyl chloride and ammonium metatungstate solution. The as-prepared catalysts were characterized by using XRD, Laser Raman spectroscopy and BET. Acetyl salicylic acid was synthesized from salicylic acid and acetic anhydride using as-synthesized WO3/ZrO2. The effects of WO3 concentration, reaction time, reaction temperature, molar ratio of reactants, as well as dosage of catalysts on synthesis of acetyl salicylic acid were investigated, and the reaction conditions were therefore optimized. The excellent yield (91.0%) of acetylsalicylic acid was obtained under optimized reaction conditions. The catalyst has been easily recovered and reused repeatedly with a consistent high yield.

► Green synthesis of acetyl salicylic acid with an environmentally friendly catalyst.
► The mechanism for the synthesis using WO3/ZrO2 as catalyst.
► Influence of the parameters of catalyst and the reaction conditions on the synthesis.