AbstractPhenols containing a freeortho‐position can be alkylated byortho‐t‐butyl‐phenols in the presence of catalytic amounts of aluminium phenoxide at temperatures between about 120° and 170°.Using 2‐t‐butylphenol, 2,6‐di‐t‐butyl‐phenol or ‐p‐cresol as the alkylating agent, trans‐t‐butylations were carried out with the following phenolic acceptors: phenol,o‐,m‐,p‐cresol,p‐Br‐,p‐Cl‐,p‐F‐,p‐CH3O‐,p‐t‐Bu‐,p‐isoPr‐, andp‐Et‐phenol. Higher rates were observed for the more acidic phenols.The above mentioned reactions lead to equilibria of the type: 2,6‐di‐t‐butyl‐p‐Z‐C6H2OH +p‐Z‐C6H4OH ⇄ 2 2‐t‐butyl‐p‐Z‐C6H3OHThe equilibrium constant for this reaction is about 24 and independent of the substituent in the phenolic nucleus.For Z = CH3the energy of activation has the value 36 (± 3) kcal/mole.When the 3, 4 and 5 positions are unoccupied, a slowortho‐paraisomerization takes place along withortho‐trans‐t‐butylation.The equilibrium between 2‐t‐butylphenol and 4‐t‐butylphenol lies far towards the thermodynamically more stablepara‐isomer, theortho‐isomer however is kinetically more favourable.Meta‐isomers are formed under these conditions to a small extent and only after long reaction times.At temperatures above 140° some dealk