Novel alkali-promoted hydrotalcite for selective synthesis of 2-methoxy phenyl benzoate from guaiacol and benzoic anhydride

Abstract

Esters find several applications such as solvents, flavours and fragrants and intermediates in synthesis of drugs. In the present work, 2-methoxy phenyl benzoate was efficiently synthesized from guaiacol and benzoic anhydride by acylation. A variety of catalysts such as hydrotalcite and alkali-promoted hydrotalcite was synthesized. Potassium-promoted hydrotalcite (K/HT) calcined at 500 °C for 6 h was active, selective and reusable. It was characterized by different techniques. A slurry batch reactor was used to study reaction mechanism and kinetics. 2-Methoxy phenyl benzoate was efficiently obtained with 100% selectivity at guaiacol conversion of 98% over K/HT at 100 °C after 6 h. A power law model with second-order kinetics was fitted to obtain an apparent activation energy of reaction of 21.1 kcal mol⁻¹. The process is clean and green.