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:
Jan. 01, 1991
Filed:
Sep. 29, 1989
Applicant:
Inventors:
Detlef-Ingo Schutze, Cologne, DE;
Reinold Schmitz, Odenthal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562421 ; 560 44 ; 562457 ;
Abstract
A process for the preparation of 2,5-diarylaminoterephthalic acids by oxidation of 2,5-diarylamino-3,6-dihydroterephthalic acid esters using oxygen or oxygen-containing gases, preferably air, in alcoholic-alkaline or alcoholic-aqueous-alkaline solution or suspension in the presence of an oxygen-transferring agent and working up to give the 2,5-diarylaminoterephthalic acids, characterized in that the oxidation is carried out in the presence of quaternary ammonium compound.