The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 1981
Filed:
Feb. 17, 1977
Shell Oil Company, Houston, TX (US);
Abstract
An improved process is described for the preparation of 2,3,5-trimethylhydroquinone by catalytically oxidizing a trimethylphenol selected from the class consisting of 2,3,5-trimethylphenol, 2,3,6-trimethylphenol and mixtures thereof with oxygen in the presence of a cobalt chelate catalyst complex in a dimethylformamide solvent to form 2,3,5-trimethyl-p-benzoquinone which is subsequently hydrogenated to 2,3,5-trimethylhydroquinone by reaction with hydrogen in the presence of a noble metal catalyst. In this improved process, the 2,3,5-trimethyl-p-benzoquinone-containing reaction mixture from catalytic oxidation is contacted with di-n-butyl ether and water to form a di-n-butyl ether phase containing the 2,3,5-trimethyl-p-benzoquinone, a precipitate comprising the cobalt catalyst and an aqueous phase containing the dimethylformamide solvent, said di-n-butyl ether phase being subsequently separated from the precipitate and aqueous phase and passed to the catalytic hydrogenation reaction where the di-n-butyl ether functions as the reaction solvent.