Catalytic hydroxylation of 2,3,6-trimethylphenol with hydrogen peroxide over copper hydroxyphosphate(Cu2(OH)PO4)

Catalytic hydroxylation of 2,3,6-trimethylphenol with hydrogen peroxide over copper hydroxyphospate Cu-2(OH)PO4 was studied. Catalytic data shows that the Cu-2(OH)PO4 catalyst is active, giving the theoretical conversion at 40.2%. The main products in this reaction are trimethylhydroquinone and trimethylbenzoquinone; there is particularly high selectivity for trimethylhydroquinone. When the reaction is carried out in air, the selectivity for trimethylhydroquinone is at 72.2% and when the reaction is carried out under N-2, the selectivity is at 94.7%. The other important factors associated with the catalytic properties have been investigated extensively. (C) 2002 Elsevier Science B.V. All rights reserved.