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:
Jul. 21, 1998
Filed:
Sep. 24, 1996
Applicant:
Inventors:
Colin Dennis Campbell, Claymont, DE (US);
Damien Thurber Cole, Upper Darby, PA (US);
Harold Raymond Taylor, III, Wilmington, DE (US);
Assignee:
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; C07D / ;
U.S. Cl.
CPC ...
560 48 ; 546 58 ; 560126 ;
Abstract
Dialkyl succinylsuccinates are prepared in a pure form and in high yield by reacting an alkali metal alcoholate with an excess of dialkyl succinate under anhydrous conditions followed by isolation of the di(alkali metal) salt of the dialkyl succinylsuccinate and then neutralization of the salt with acid. The resulting dialkyl succinylsuccinate is isolated or used without isolation as an intermediate in the production of quinacridone pigments. The disclosed process provides for high yields and reduced organic waste compared with known processes.