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. 27, 2007
Filed:
Dec. 14, 2004
Helmut-werner Heuer, Krefeld, DE;
Rolf Wehrmann, Krefeld, DE;
Helmut-Werner Heuer, Krefeld, DE;
Rolf Wehrmann, Krefeld, DE;
H.C. Starck GmbH & Co. KG, Goslar, DE;
Abstract
A process for the production of 3,4-dioxythiophene compounds represented by the following formula (I), is described. In formula (I) A, B, C and D in each case independently denote a bond, optionally substituted alkylene, optionally substituted cycloalkylene, optionally substituted arylene or (O—(CRR)), where Rand Rin each case mutually independently denote hydrogen or optionally substituted alkyl, m denotes an integer from 1 to 10 and x denotes an integer from 1 to 10, provided that at least one of the units A, B, C or D does not denote a bond. The process involves reacting a 3,4-dihydroxythiophene or the alkali metal salt thereof with the following compound,TosO-A-B-C-D-OTos,thus forming an intermediate 3,4-dioxythiophene diester. The intermediate 3,4-dioxythiophene diester is saponified, thus forming an intermediate 3,4-dioxythiophene dicarboxylic acid, which is then decarboxylated, thereby forming the 3,4-dioxythiophene compound represented by formula-(I).