Method for the production of trimethylhydroquinone
AssigneeDegussa AG
InventorsFrank Hubner, Steffen Krill, Bernd Drapal, Hermann Schmitt, Klaus Huthmacher, Herbert Tanner
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Abstract
The invention relates to an improved method for the production of 2,3,5-trimethylhydroquinone by rearranging 4-oxo-isophorone (keto-isophorone, 3,5,5-trimethylcyclohex-2-en[e]-1,4-dione) to a trimethylhydroquinone diester and by its subsequent saponification. ##STR1##
Claims2
A method of producing trimethylhydroquinone (TMHQ) by reacting ketoisopherone with an acylating agent in the presence of catalytic amounts of protonic acid to form a trimethylhydroquinone ester, and subsequently saponifying the trimethylhydroquinone ester, wherein the acid is trifluoromethane sulfonic acid, chlorosulfonic acid, polyphosphoric acid or oleum or mixtures of these acids, and wherein TMHQ diacetate produced is separated from the reaction mixture after the addition of water and saponified using dilute acid in the presence of a phase agent, and TMHQ produced thereby is separated off.
Dependencies are inferred from the claim text.