Patent ID: 6441249
Filing Date: 2002-08-27
Classification: C07C

Abstract:
A method for producing trimethylhydroquinone comprising:oxidizing &bgr;-isophorone in the presence of amorphous carbon and an oxidation-resistant nitrogen-containing heterocyclic base to obtain 4-oxoisophorone and to separate 4-oxoisophorone by distillation to obtain highly pure 4-oxoisophorone; reacting said highly pure 4-oxoisophorone in a liquid phase with an excess of an acid anhydride in the presence of a solid acid catalyst to obtain at least one compound represented by the following formula [I]: wherein R1 and R2 may be the same or different and are selected from hydrogen or an acyl group;recovering at least part of unreacted acid anhydride; and hydrolyzing compounds having at least one acyl group in the obtained reaction product represented by formula [I], thereby obtaining trimethylhydroquinone.