Alkylation of Phenol with Cyclohexene

The alkylation of phenol with cyclohexene in the vapor phase has been studied over the cation-exchanged X zeolite catalysts. Because of the dealkylation of products, the catalytic activity decreased with rising reaction temperature. The yield of cyclohexylphenol increased linearly with increase in the amount of acid. Furthermore, the catalytic activity decreased by the addition of pyridine. However, the order of catalytic activity for alkylation of phenol with cyclohexene was not in accord with that for the cracking of cumene. On the other hand, the volcanoshape relation was observed between the catalytic activity for alkylation of phenol with cyclohexene and the electronegativity of metal ion in the catalyst. On the basis of these results, it is concluded that the alkylation reaction proceeds on the acid sites, and the active sites are the surface protons and the metal ions of the catalyst.