Azido-PEG4-t-butyl acetate

Azido-PEG4-CH2CO2-t-butyl ester is a PEG reagent containing an azide group and a t-butyl protected carboxyl group. The azide group enables Click Chemistry. The protected carboxyl group (COOH) prevents self coupling or polymerization under standard acid/amine or acid/hydroxyl coupling conditions. t-butyl ester can be deprotected by acidic or basic hydrolysis. The hydrophilic PEG spacer increases solubility in aqueous media.

Azido-PEG4-CH2-Boc is a cleavable 4 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1]. Azido-PEG4-CH2-Boc is also a PEG- and Alkyl/ether-based PROTAC linker that can be used in the synthesis of PROTACs[2]. Azido-PEG4-CH2-Boc 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; Alkyl/ether; Cleavable Linker

[1] Shiladitya Sengupta, et al. Targeted drug delivery through affinity based linkers. WO2015148126A1.
[2] Zhang F, et al. Discovery of a new class of PROTAC BRD4 degraders based on a dihydroquinazolinone derivative and lenalidomide/pomalidomide. Bioorg Med Chem. 2020 Jan 1;28(1):115228. DOI:10.1016/j.bmc.2019.115228