Heterobifunctional poly(ethylene glycol) derivatives and methods for their preparation
AssigneeNektar Therapeutics
InventorsMichael D. Bentley, J. Milton Harris, Antoni Kozlowski
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Abstract
This invention provides a method related to the preparation of derivatives of poly(ethylene glycol), wherein the method comprises increasing the pH of an aqueous composition comprising a poly(ethylene glycol) bearing a —O—(CH2)n—CO2R3 functional group to result in an aqueous composition comprising a poly(ethylene glycol) bearing a —O—(CH2)n—CO2H functional group, wherein R3 is alkyl and (n) in each instance is 1-6.
Claims8
A method comprising (a) increasing the pH of an aqueous composition comprising —CH2CH2O(CH2CH2O)nCH2CH2— bearing a —O—(CH2)n—CO2R3 functional group and a benzyloxy group, and wherein the molecular weight of
- the —CH2CH2O(CH2CH2O)nCH2CH2— is between 3400 and 176000, and (b) subsequently adjusting the pH of the aqueous composition with an acid to result in an aqueous composition comprising —CH2CH2O(CH2CH2O)nCH2CH2— bearing a —O—(CH2)n—CO2H functional group and a benzyloxy group, and further wherein R3 is tert-butyl, (n) in each instance of —O—(CH2)n—CO2R3 and —O—(CH2)n—CO2H is 1-6, and the molecular weight of the —CH2CH2O(CH2CH2O)nCH2CH2— is between 3400 and 176000.
Dependencies are inferred from the claim text.