Back to results
US 5,681,567 AGranted
Method of preparing polyalkylene oxide carboxylic acids
AssigneeEnzon, Inc.
InventorsAnthony J. Martinez, Richard B. Greenwald
Life of this patent
Estimating the term…
Abstract
The present invention is directed to methods of preparing high purity polyalkylene oxide carboxylic acids. The methods include reacting a polyalkylene oxide such as polyethylene glycol with a t-butyl haloacetate in the presence of a base followed by treatment with an acid such as trifluoroacetic acid. The resultant polymer carboxylic acids are of sufficient purity so that expensive and time containing purification steps required for pharmaceutical grade polymers are avoided.
Claims26
A method of preparing a biologically active conjugate, comprising:
- i) reacting a polyalkylene oxide with a tertiary alkyl haloacetate in the presence of a base to form a tertiary alkyl ester of polyalkylene oxide;
- ii) reacting said tertiary alkyl ester with an acid to form a polyalkylene oxide containing a terminal carboxylic acid;
- and
- iii) reacting said polyalkylene oxide containing said terminal carboxylic acid with a biologically active nucleophile under conditions sufficient to form a biologically active conjugate whereby said polyalkylene oxide is linked to said biologically active nucleophile by an ester linkage.
1 more element
Dependencies are inferred from the claim text.