para-Selective t-butylation of phenol over mesoporous H-AlMCM-41

Vapour phase alkylation of phenol with t-butyl alcohol (2-methyl-2-propanol) was carried out over mesoporous H-AlMCM-41 in the temperature range 448-498 K. In this reaction, p-t-butyl phenol was obtained as a major product with high selectivity. While the phenol conversion increases with a decrease in phenol-to-t-butyl. alcohol ratio, the catalytic activity decreases with time-on-stream due to deactivation of the catalyst. At higher temperatures, both the ortho- and para-isomers, viz., o-t-butyl phenol and p-t-butyl phenol, undergoes isomerization leading to m-t-butyl phenol. (C) 2000 Elsevier Science B.V. All rights reserved.