Selective synthesis of 2- t-butylated hydroxyl anisole by t-butylation of 4-methoxyphenol with t-butyl alcohol over mesoporous solid acid catalysts

Abstract

t-Butylation of 4-methoxyphenol (4-MP) with t-butylalcohol ( t-BuOH) as alkylating agent have been conducted under liquid phase reaction conditions over Zn–Al-MCM-41 catalysts with different n Si/( n Zn + n Al) ratios for selective synthesis of 2- t-butlylated hydroxyl anisole (2-TBHA). The influences of various reaction parameters such as reaction temperature, time and t-BuOH to 4-MP ratios on the conversion of 4-MP and the selectivity of 2-TBHA have also been studied. With the decrease of the n Si/( n Zn + n Al) ratios of Zn–Al-MCM-41 catalysts from 380 to 75, the conversion of 4-MP as well as the yield and selectivity of 2-TBHA increase due to the increase of the number of Brønsted acid sites in Zn–Al-MCM-41 catalysts. The n Si/( n Zn + n Al) ratio of 75 is found to be the most suitable and reusable for the t-butylation of 4-MP with t-BuOH for selective synthesis of 2-TBHA.