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. 05, 1993
Filed:
Apr. 22, 1991
Barbara J Wagner, Charleston, SC (US);
Bernd Kaletta, Leverkusen, DE;
Miles Inc., Pittsburgh, PA (US);
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
This invention relates to a process for preparing asymmetric isoindoline pigments of the formula ##STR1## in which R.sup.1 is an electron-withdrawing group, R.sup.2 and R.sup.3 are independently hydrogen, alkyl, or aryl, and R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are independently hydrogen, halogen, alkyl, alkoxy, or aryloxy. The process employs an initial reaction of a 1,2-dicyanobenzene with an alcohol in an organic medium in the presence of a base. The resultant imino-isoindoline intermediate composition reacts without isolation with a cyanomethylene compound NC--CH.sub.2 --R.sup.1 to form a partly condensed product that is then condensed without isolation in the presence of water with barbituric acid or a derivative thereof to form the asymmetric isoindoline pigment.