Method of preparing polyalkyene oxide carboxylic acids
First Claim
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1. A method of preparing an amine-terminated polyalkylene oxide 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) converting said polyalkylene oxide containing said terminal carboxylic acid to an amine-terminated polyalkylene oxide.
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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 trifloroacetic acid. The resultant polymer carboxylic acids are of sufficient plurty so that expensive and time consuming purification steps required for pharmaceutical grade polymers are avoided.
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24 Claims
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1. A method of preparing an amine-terminated polyalkylene oxide comprising:
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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) converting said polyalkylene oxide containing said terminal carboxylic acid to an amine-terminated polyalkylene oxide. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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2. A method of preparing a succinimidyl ester-terminated polyalkylene oxide comprising:
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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) converting said polyalkylene oxide containing said terminal carboxylic acid to an succinimidyl ester-terminated polyalkylene oxide.
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Specification