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:
Aug. 30, 2016
Filed:
Oct. 23, 2013
Applicant:
Uhde Inventa-fischer Gmbh, Berlin, DE;
Inventors:
Assignee:
UHDE INVENTA-FISCHER GMBH, Berlin, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D 319/06 (2006.01); C07D 319/12 (2006.01);
U.S. Cl.
CPC ...
C07D 319/12 (2013.01);
Abstract
The present invention relates to a method for the production of cyclic carboxylic acid esters, in particular intramolecular lactones, such as e.g. dilactide, the production of these cyclic esters from oligomeric carboxylic acids being effected by cyclizing depolymerization. During this reaction, a condensation product of these oligomeric carboxylic acids is produced as by-product, i.e. a mixture of higher-molecular oligomeric carboxylic acids which are hydrolyzed in a further step and hence recovered. This hydrolysate can be added again to the cyclizing depolymerization which is implemented in the first step.