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. 30, 1980
Filed:
Dec. 05, 1979
Applicant:
Inventors:
Otto Arndt, Hofheim am Taunus, DE;
Bernhard Mees, Ehlhalten, DE;
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
2605 / ;
Abstract
Pure toluene-4-sulfonic acid is obtained without forming any by-products by sulfonating toluene with sulfuric acid at an elevated temperature, separating a first batch of toluene-4-sulfonic acid hydrate, washing it free of isomers with sulfuric acid, combining the mother liquor and the washing effluent, heating them, allowing a second batch of hydrate to crystallize and, optionally, working up the final mother liquor by hydrolizing the toluene sulfonic acids therein and recycling the toluene so formed and the sulfuric acid after concentrating it to its initial strength.