Alkylation of phenol with cyclohexene catalysed by cationic ion-exchange resins and acid-treated clay: O- versus C-alkylation

Abstract

Alkylation of phenol with cyclohexene was carried out in the presence of different cation-exchangers and acid-treated clay (Filtrol-24) as catalysts in the temperature range 45-120°C. The role of homogeneous catalysts such as 50% aqueous solution of ρ-toluenesulfonic acid (PTSA) and 98% H₂SO₄ was also assessed. This reaction is unique in that a substantial amount of cyclohexyl phenyl ether is formed at lower temperature, which may well have good perfumery value. Amberlyst-15 was the best catalyst so far as the activity was concerned. Selective Ο-alkylation can be obtained in the presence of Filtrol-24 as catalyst in the temperature range 45-60°C. The suitability of cyclohexanol as the alkylating agent was assessed. It can be used for C-alkylation in the temperature range 180-250°C in the presence of Filtrol-24 as catalyst.