US 7,544,738 B2
	Method for the preparation of 1-benzotriazolyl carbonate esters of poly(ethylene glycol)
Antoni Kozlowski, Huntsville, Ala. (US)
Assigned to Nektar Therapeutics AL, Corporation, Huntsville, Ala. (US)
Filed on Apr. 25, 2008, as Appl. No. 12/150,136.
Application 10/068371 is a division of application No. 09/740556, filed on Dec. 18, 2000, granted, now 6,376,604.
Application 12/150136 is a continuation of application No. 11/492133, filed on Jul. 24, 2006, granted, now 7,378,469.
Application 11/492133 is a continuation of application No. 10/727337, filed on Dec. 02, 2003, granted, now 7,101,932.
Application 10/727337 is a continuation of application No. 10/068371, filed on Feb. 06, 2002, granted, now 6,710,125.
Claims priority of provisional application 60/171834, filed on Dec. 22, 1999.
Prior Publication US 2008/0227872 A1, Sep. 18, 2008
This patent is subject to a terminal disclaimer.
Int. Cl. C08F 16/06 (2006.01); C08F 116/06 (2006.01); C07D 249/08 (2006.01)

U.S. Cl. 525—54.2  [525/56; 525/60; 548/269.4]

3 Claims

1. A polymer conjugate composition comprising a polymer conjugate prepared by reacting a water-soluble and non-peptidic polymer reagent composition with a biologically active agent to form the polymer conjugate composition, wherein the water-soluble and non-peptidic polymer reagent comprises a maleimide functional group and the water-soluble and non-peptidic polymer reagent is prepared by a method comprising the steps of (i) reacting a terminal hydroxyl group of a water-soluble and non-peptidic polymer bearing a terminal hydroxyl group with di(1-benzotriazolyl)carbonate to form a 1-benzotriazolylcarbonate ester of the water-soluble and non-peptidic polymer, (ii) reacting the 1-benzotriazolylcarbonate ester of the water-soluble and non-peptidic polymer with lysine to form a water-soluble and non-peptidic lysine derivative, and (iii) using the polymer lysine derivative in the formation of the water-soluble and non-peptidic reagent.