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:
Apr. 01, 1980
Filed:
Mar. 31, 1978
Jean Claude Vallejos, Paris, FR;
Yani Christidis, Paris, FR;
Hoechst France, Puteaux, FR;
Abstract
The process for manufacturing thienyl-2 acetic acid from acetylthiophene comprises condensing acetylthiophene at a temperature below 120.degree. C. with an excess of a C.sub.4 to C.sub.8 aliphatic primary amine or with a cyclic amine, in the presence of an acid catalyst and removing the water formed, so as to obtain the corresponding imine. The imine is reacted with excess sulfur at a temperature equal to or below 100.degree. C. in a basic and aprotic solvent to produce the corresponding thioamide. The thioamide is hydrolyzed by the action of an excess of a strongly alkaline base in a C.sub.4 to C.sub.8 alcohol or in ethylene glycol, if necessary in the presence of water, so as to obtain an alkali salt of thiophene-2 acetic acid. Finally the latter is treated with a strong acid in aqueous solution to liberate the thienyl-2 acetic acid.