Acetylation of Alcohols in the presence of FeCl۳/SiO۲nanoparticles

The conversion of alcohols to esters is an important synthetic transformation that has receivedconsiderable attention. This method is important because of the ease of introduction of the acetylgroup, the stability of the product to acidic conditions, and ease of removal of the protectinggroup by alkaline hydrolysis [۱].A variety of procedures are routinely performed for the preparation of acetyl derivatives underhomogeneous or heterogeneous catalysts. Typically, the acetylation of hydroxyl groups isperformed with an excess acetic anhydride in the presence of a convenient basic (pyridine ortriethylamine, DMAP) catalyst [۲] or protic acids such as sulfamic acid [۳] and Lewis acids suchas LiCl [۴].Nevertheless, there is still a great demand for acid catalysts to generate esters under mildconditions. Therefore, we present an efficient procedure for the acetylation of alcohols withacetic anhydride in the presence of a catalytic amount of a heterogeneous catalyst, nano silicasupported ferric chloride (FeCl۳/SiO۲ nanoparticles). All reactions were performed at ۹۰°C andunder solvent free conditions.Nano silica supported ferric chloride is an effective catalyst for acylation of alcohols and it wasable to promote the reactions with good to excellent yields. All the products were characterizedby FT-IR spectra, melting point and comprised with authentic samples.