Chloroacetamido-PEG4-NHS ester is a PEG linker containing chloroacetamide and NHS ester functional groups. The chlorine is a good leaving group and can undergo substitution reactions. The NHS ester is an active ester which reacts with primary amines to form stable amide bonds. The hydrophilic PEG linker increases the hydrophilic properties of the compound in aqueous media.
