A TFAA–H3PO4-mediated direct, metal-free and high-speed synthesis of aryl carboxylate esters from phenols

An operationally simple, mild and single-step method for the direct and metal-free synthesis of aryl carboxylate esters is described under a solvent free condition. The reaction of phenols including 2-naphthol (or 1-naphthol) with a variety of carboxylic acids in the presence of TFAA and 85% H3PO4 provided a range of aryl carboxylate esters in good yields within few minutes.

We disclose TFAA–H3PO4-mediated direct O-acylation of phenols and 2-naphthol (or 1-naphthol) using a free carboxylic acid without generating any C-acylated side products. The present methodology works well either at room temperature or at 50 °C and provides the O-acylated products in good to excellent yields within few minutes.Figure optionsDownload as PowerPoint slide