PROCESS FOR THE PRODUCTION OF 2,3,5-TRIMETHYLHYDROQUINONE DIESTERS

摘要

This invention relates to a process for the production of 2,3,5-trimethylhydroquinone diesters by aromatisation of 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone, ketoisophorone, KIP) with an acylating agent and an acidic soluble or insoluble catalyst, which process may be operated alternatively continuously or discontinuously. A carboxylic anhydride having a C1 to C9 alkyl residue is used as the acylating agent, and after the reaction, a portion of the resultant carboxylic acid optionally may be removed by distillation. The reaction solution is cooled, the product which has crystallised out is separated and washed, and the filtrate is returned to the reaction.