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.

Date of Patent:
Sep. 07, 2021

Filed:

Jun. 05, 2018
Applicant:

Nektar Therapeutics, San Francisco, CA (US);

Inventors:

J. Milton Harris, Huntsville, AL (US);

Antoni Kozlowski, Huntsville, AL (US);

Lihong Guo, Plano, TX (US);

Assignee:

Nektar Therapeutics, San Francisco, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G 65/332 (2006.01); C08G 63/91 (2006.01); C08G 65/334 (2006.01); A61K 31/765 (2006.01); C08F 251/00 (2006.01); C08F 261/04 (2006.01); C08F 265/00 (2006.01); C08F 271/00 (2006.01); C08F 283/06 (2006.01); C08F 289/00 (2006.01); C08F 291/00 (2006.01); C08G 65/30 (2006.01);
U.S. Cl.
CPC ...
C08G 63/91 (2013.01); A61K 31/765 (2013.01); C08F 251/00 (2013.01); C08F 261/04 (2013.01); C08F 265/00 (2013.01); C08F 271/00 (2013.01); C08F 283/06 (2013.01); C08F 289/00 (2013.01); C08F 291/00 (2013.01); C08G 65/30 (2013.01); C08G 65/332 (2013.01); C08G 65/3322 (2013.01); C08G 65/3346 (2013.01);
Abstract

Methods for preparing water soluble, non-peptidic polymers carrying carboxyl functional groups, particularly carboxylic acid functionalized poly(ethylene glycol) (PEG) polymers are disclosed, as are the products of these methods. In general, an ester reagent R(C═O)OR', wherein R′ is a tertiary group and R comprises a functional group X, is reacted with a water soluble, non-peptidic polymer POLY-Y, where Y is a functional group which reacts with X to form a covalent bond, to form a tertiary ester of the polymer, which is then treated with a strong base in aqueous solution, to form a carboxylate salt of the polymer. Typically, this carboxylate salt is then treated with an inorganic acid in aqueous solution, to convert the carboxylate salt to a carboxylic acid, thereby forming a carboxylic acid functionalized polymer.


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