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:
Jun. 26, 1990
Filed:
Oct. 06, 1988
Applicant:
Inventors:
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
546103 ; 546 49 ;
Abstract
A process for the preparation of 2-(arylamino)-3-carboxy-9(10H)-acridones of the formula A ##STR1## in which R and R' represent hydrogen, fluorine, chlorine or bromine atoms, alkyl(C.sub.1 -C.sub.4)-, oxalkyl(C.sub.1 -C.sub.4)- or carbonamide groups and x and y denote integers from 1 to 4, by cyclizing 2,5-diarylaminoterephthalic acids of the formula D ##STR2## in which R, R', x and y have the meanings mentioned previously, in a 5- to 15-fold amount by weight of polyphosphoric acid (P.sub.4 O.sub.10 content 80 to about 85%) or of an acidic polyphosphate (P.sub.4 O.sub.10 contents 75 to about 85%) as a water-abstracting agent at about 60.degree. C. to about 100.degree. C.