3-[2-[2-[2-(2-Azidoethoxy)ethoxy]ethoxy]ethoxy]propanoic acid hydrazide

Azido-PEG4-hydrazide HCl salt is a PEG linker containing an azide group and a hydrazide group. The hydrophilic PEG spacer increases solubility of a compound in aqueous media. The azide group can react with alkyne, BCN, DBCO via Click Chemistry to yield a stable triazole linkage. The hydrazide group can react with an aldehyde to form a semi-permanent hydrozone bond.

Azido-PEG4-hydrazide is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs[1]. Azido-PEG4-hydrazide is a click chemistry reagent, it contains an Azide group and can undergo copper-catalyzed azide-alkyne cycloaddition reaction (CuAAc) with molecules containing Alkyne groups. It can also undergo strain-promoted alkyne-azide cycloaddition (SPAAC) reactions with molecules containing DBCO or BCN groups.

PEGs

[1] An S, et al. Small-molecule PROTACs: An emerging and promising approach for the development of targeted therapy drugs. EBioMedicine. 2018 Oct;36:553-562 DOI:10.1016/j.ebiom.2018.09.005