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

Claim 37:
38. A method for preparing an N-hydroxyl succinimidyl carbonate ester-activated polymeric reagent, said method comprising:
reacting a water-soluble 9-hydroxymethyl fluorene polymer having a structure:, 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;
Re2, when present, is a second electron-altering group;
L1 is a first linking moiety;
L2 is a second linking moiety;
Re1, which may or may not be present, is a first electron-altering group; and
Re2, which may or may not be present, is a second electron-altering group;
with from about 1 to 20 equivalents of disuccinimidyl carbonate in an anhydrous aprotic organic solvent in the presence of a base to provide a reaction mixture comprising a water-soluble 9-methyl N-hydroxysuccinimidyl 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 N-hydroxysuccinimidyl carbonate fluorene polymer of structure (III) from the reaction mixture.