Used as an intermediate in the synthesis of pharmaceutical compounds, particularly in the development of modified biomolecules and prodrugs. Its structure allows for selective conjugation with active ingredients to improve solubility, stability, and bioavailability. Commonly employed in the preparation of polymer-drug conjugates and in bioconjugation techniques for targeted delivery systems. Also utilized in research settings for labeling and immobilization of biologically active molecules due to its reactive sulfonate ester group and polyether backbone.