IP Library Granted Patent US 8,193,306
Granted Patent B2
US 8,193,306 · App. 12/820,124 · Granted Jun 5, 2012

Methods for preparing polymeric reagents and compositions of polymeric reagents

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Quick Facts
Patent No.
US 8,193,306
App. No.
12/820,124
Granted
Jun 5, 2012
Kind
B2
Abstract

Methods for preparing active carbonate esters of water-soluble polymers are provided. Also provided are other methods related to the active carbonate esters of water-soluble polymers, as well as corresponding compositions.

Claims (11)

1. A synthetic method comprising:

(a) combining a composition comprising an aprotic solvent and a hydroxy-terminated, water-soluble polymer having the following structure:

CH 3 O—(CH 2 CH 2 O) n —CH 2 CH 2 —OH

wherein (n) is an integer from 2 to about 4000, with a composition comprising di(1-benzotriazolyl) carbonate, wherein the composition comprising the di(1-benzotriazolyl) carbonate is added such that there is an excess of the di(1-benzotriazolyl) carbonate relative to the hydroxy-terminated, water-soluble polymer, to thereby result in a composition comprising an active carbonate ester of the water-soluble polymer having the following structure:

wherein (n) is an integer from 2 to about 4000, and unreacted di(1-benzotriazolyl) carbonate;

(b) adding a composition comprising a reactive molecule selected from the group consisting of water, a lower alkyl monohydric alcohol, hydrogen sulfate and a lower alkyl monobasic amine to the composition comprising the active carbonate ester of a water-soluble polymer and unreacted di(1-benzotriazolyl) carbonate, wherein the composition comprising the reactive compound is added such that substantially all of the unreacted di(1-benzotriazolyl) carbonate is substantially consumed; and

(c) reacting the active carbonate ester of a water-soluble polymer lysine to form a polymeric lysine derivative.

2. The method as in claim 1 , wherein the reactive molecule is selected from the group consisting of water, a lower alkyl monohydric alcohol, hydrogen sulfide, and a lower alkyl monobasic amine.

3. The method as in claim 1 , wherein the reactive molecule is selected from hydroxyalkyl attached to a solid support, mercaptoalkyl attached to a solid support, primary amine attached to a solid support, and secondary amine attached to a secondary support.

4. The method as in claim 1 , wherein the polymeric lysine derivative has the following structure:

wherein each (n) is an integer from 2 to about 4000.

Assignments (4)
RELEASE OF SECURITY INTEREST Recorded Apr 17, 2020
From: TC LENDING, LLC, AS COLLATERAL AGENT
To: NEKTAR THERAPEUTICS
Reel/Frame 053180/0009 →
RELEASE OF SECURITY INTEREST RECORDED AT REEL 28571, FRAME 0141 Recorded Oct 14, 2015
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: NEKTAR THERAPEUTICS
Reel/Frame 036866/0700 →
GRANT OF SECURITY INTEREST IN UNITED STATES PATENTS Recorded Oct 6, 2015
From: NEKTAR THERAPEUTICS
To: TC LENDING, LLC, AS COLLATERAL AGENT
Reel/Frame 036796/0562 →
GRANT OF SECURITY INTEREST Recorded Jul 17, 2012
From: NEKTAR THERAPEUTICS
To: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 028571/0141 →