Green alkylation of anisole with cyclohexene over 20% cesium modified heteropoly acid on K-10 acidic montmorillonite clay

Abstract

Alkylation of anisole with cyclohexene is an industrially important reaction. It was carried out in the liquid phase using in a number of solid acids as catalysts. Acid treated clay (K-10) as support with 20% m/m 20%Cs_2.5H_0.5PW₁₂O₄₀ (cesium modified dodecatungstophosphoric acid; designated as Cs-DTP/K-10), with nano-sized particles, was found to be the best catalyst. This reaction leads to formation of 2-cyclohexylanisole and 4-cyclohexylanisole, which have been used as perfumery compounds and also as precursors to synthesise several commercial products. Conversion of cyclohexene was found to be 96% after 3 h at 105 °C. No oligomerisation of cyclohexene was observed under the optimized reaction conditions. Effect of different parameters on rate of reaction was studied systematically and the kinetics of reaction deduced.