Method for producing trimethylhydroquinone
AssigneeNippon Petrochemicals Company, Limited
InventorsKazuharu Suyama, Noboru Kiyota, Tomohiro Konishi, Yasuo Matsumura
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Abstract
An inexpensive method for producing trimethylhydroquinone free from the problem of the disposal of waste catalyst, which method comprises the steps of: (1) reacting isophorone in the presence of an acid catalyst and recovering β-isophorone by distiiulation, (2) oxidizing the β-isophorone in the presence of amorphous carbon and a base to obtain 4-oxoisophorone, (3) reacting the 4-oxoisophorone with an acid anhydride in a liquid phase or with a carboxylic acid in a vapor phase in the presence of a solid acid catalyst to obtain trimethylhydroquinones, and (4) hydrolyzing the trimethylhydroquinones to obtaining trimethylhydroquinone.
Claims20
A method for producing trimethylhydroquinone comprising:
- oxidizing β-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.
A method for producing trimethylhydroquinone comprising:
- oxidizing β-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 with at least one member selected from acid anhydrides or carboxylic acids 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;
- and
- hydrolyzing compounds having at least one acyl group in the obtained reaction product represented by formula [I], thereby obtaining trimethylhydroquinone.
A method for producing 4-oxoisophorone comprising:
- oxidizing β-isophorone in the presence of amorphous carbon and an oxidation-resistant nitrogen-containing heterocyclic base to obtain 4-oxoisophorone.
Dependencies are inferred from the claim text.