Synthesis of <i style="">p</i>-tolyl stearate catalyzed by acid activated Indian bentonite

Abstract

Synthesis of <i style="">p</i>-tolyl stearate, catalyzed by acid activated Indian bentonite (AAIB) is reported. The esterification of stearic acid (SA) and <i style="">p</i>-cresol (<i style="">p</i>-C) gave <i style="">p</i>-tolyl stearate in high yield using acid activated Indian bentonite as the catalyst. White montmorillonite exchanged with Al³⁺ and treated with HCl gave 49 and 51% of the ester respectively after 12 h. Use of <i style="">p</i>-toluenesulphonic acid as catalyst gave 82% yield of the ester after 12 h in toluene. When the reaction was conducted in toluene and <i style="">o</i>-xylene with Indian bentonite treated with H₂SO₄ the yields were 89 and 97% (molar ratio, SA:<i style="">p</i>-C = 1:4) respectively after 12 h. Effects of molar ratio, amount of the catalyst, solvent, reaction time and catalyst activation temperature on the yield of <i style="">p</i>-tolyl stearate and reusability of the clay catalyst are investigated.