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:
Dec. 01, 2009
Filed:
Oct. 23, 2002
Werner Bonrath, Freiburg, DE;
David Carl Burdick, Peoria, IL (US);
Frank Schager, Loerrach, DE;
Dominik Thomas, Munich, DE;
Thomas Netscher, Bad Krozingen, DE;
Werner Bonrath, Freiburg, DE;
David Carl Burdick, Peoria, IL (US);
Frank Schager, Loerrach, DE;
Dominik Thomas, Munich, DE;
Thomas Netscher, Bad Krozingen, DE;
DSM IP Assets B.V., TE Heerlen, NL;
Abstract
A process for the manufacture of (all-rac)-α-tocopherol comprises submitting isolated, purified phytyltrimethylhydroquinone to acid catalysis, thereby promoting ring closure to (all-rac)-α-t-tocopherol. The process can be conducted in the absence or presence of an added solvent, and when a solvent or solvent mixture is used the solvent or at least one solvent component of the solvent mixture is preferably one with a dipole moment greater than 9×10C-m (or 2.7D). The nature of the catalyst is immaterial, but the catalyst is preferably sulphuric acid, phosphoric acid, a polyperfluoroalkylenesulphonic acid, a 'NH-acid', a heteropoly acid, zinc chloride, boron trifluoride, aluminium trichloride, or a mixture of any f the aforementioned Brönsted acids with any of the aforementioned Lewis acids. The product of the process is the most active an industrially most important member of the vitamin E group.