Bromoacetic-PEG1-tert-butyl ester is a PEG linker bearing a bromoacetyl moiety and a carboxyl group protected by tert-butyl ester. Structurally, a bromoacetyl group (Br-CH₂-CO–) on one terminus and a tert-butyl ester group (–COO-tBu) on the other are bridged by a monoethylene glycol (PEG1) spacer, which imparts both hydrophilicity and chemical reactivity to the molecule.

In the conventional manufacturing process, bromoacetic acid is adopted as the starting material. Esterification is carried out to attach the tert-butyl protecting group, followed by ring-opening polymerization of ethylene oxide to construct the PEG segment. A high-purity product is acquired after subsequent purification steps.

This reagent finds extensive applications in bioconjugation, drug delivery and materials science, such as the preparation of targeted drug carriers, fluorescent probes and functionalized nanomaterials. The tert-butyl ester moiety can undergo deprotection under acidic environments to expose free carboxyl groups for downstream condensation reactions.