Azido-PEG-(CH2)3-methyl ester is a chemical compound that belongs to the family of PEGylated molecules. It contains three important functional groups, namely azido, PEG, and methyl ester. The azido group is a reactive moiety that can undergo click chemistry reactions with other functional groups such as alkynes and strained cyclooctynes. The PEG group provides water solubility and biocompatibility to the molecule, making it an ideal candidate for drug delivery applications. Finally, the methyl ester group provides stability to the molecule and can be used to protect other functional groups during chemical synthesis. Azido-PEG-(CH2)3-methyl ester has been extensively used in pharmaceutical research and development for the conjugation of drugs, peptides, and proteins. Its unique properties make it an ideal platform for the synthesis of novel drug conjugates with improved pharmacokinetics and pharmacodynamics.