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. 09, 1990
Filed:
Jun. 09, 1988
Applicant:
Inventors:
Detlef-Ingo Schutze, Cologne, DE;
Klaus Wunderlich, Leverkusen, DE;
Karl-Heinz Reinhardt, Leverkusen, DE;
Martin Wienkenhover, Leverkusen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
546 98 ; 546 99 ; 546100 ;
Abstract
Process for the preparation of naphthalene-1,8-dicarboximide which is optionally substituted in the naphthalene ring, characterized in that naphthalene-1,8-dicarboxylic anhydride which is optionally substituted in the naphthalene ring is reacted with an ammonium salt in an aqueous medium at a pH near to the neutral point, the reaction mixture is then acidified to a pH of 1 to 4 and the pH is subsequently adjusted to a value near to the neutral point.