Patent ID: 11932726
Assignee: NEKTAR THERAPEUTICS
Field: Pharmaceuticals (Chemistry)
Classification: CPC C  A | IPC A  C

Claim 0:
1. A method for preparing a reactive polymeric reagent, said method comprising:
(i) reacting a water-soluble 9-hydroxymethyl fluorene polymer having a structure (I):, wherein
POLYa is a first water-soluble, non-peptidic polymer;
POLYb is a second, water-soluble non-peptidic polymer;
Re1, when present, is a first electron-altering group; and
Re2, when present, is a second electron-altering group;
L1 is a first linking moiety; and
L2 is a second linking moiety;

with dibenzotriazolyl carbonate in an aprotic organic solvent in the presence of a base under anhydrous conditions to provide a reaction mixture comprising a water-soluble 9-methyl benzotriazolyl carbonate fluorene polymer having a structure:, , wherein POLYa, POLYb, Re1, Re2, L1, and L2 each have values as described in step (i), and
(ii) recovering the water-soluble 9-methyl benzotriazolyl carbonate fluorene polymer (II) by precipitation with an anhydrous solvent effective to promote precipitation of the water-soluble 9-methyl benzotriazolyl carbonate fluorene polymer.