Acetylation of alcohols, phenols and salicylic acid by heteropoly acids in acetic anhydride: a green and eco-friendly protocol for synthesis of acetyl salicylic acid (Aspirin)

A series of eco-friendly solid acid catalysts including; Preyssler, Wells-Dowsen and Keggin HPAs have been used as catalysts for acetylation of alcohols, phenols and salicylic acid with acetic anhydride. The performance of different forms of heteropoly acids in the presence of acetic anhydride as acetylating agent for acetylation of salicylic acid was compared. In all cases, the best conditions were observed using Preyssler as catalyst.