The alkylation of phenol with isobutene

Some aspects of the alkylation of phenol with isobutene using small quantities of sulfuric acid as a catalyst are discussed. It is shown that initially ortho and para substitution take place to roughly the same extent. In the course of the reaction the isomer distribution changes in favour of the para isomer, the alkylation being reversible. Equilibrium constants were determined in the temperature range of 50-125°.