N-Ethylpropionamide-PEG1-Br

N-Ethylpropionamide-PEG1-Br, provides a compact polyethylene glycol spacer terminated with a bromide handle, enabling efficient attachment of PROTAC building blocks. Its ether-containing segment can improve conformational flexibility and solubility of conjugates, while the reactive bromide supports modular synthesis. The linker is well suited for constructing degraders through reliable carbon–heteroatom bond formation strategies, and the points below describe its structure and practical reactivity considerations in detail below.

Structure: The linker contains an ether-based PEG segment providing flexible, polar spacing, connected to an N-ethylpropionamide functionality. A terminal bromide provides a leaving group for substitution. The molecule features amide and ether linkages, with heteroatoms that enhance hydrogen-bonding and overall polarity.

Reactivity: The bromide terminus is typically used in nucleophilic substitution or related alkylation steps to install the linker onto appropriate PROTAC fragments. Suitable conditions often involve polar aprotic solvents and nucleophiles such as amines or heteroatom-containing groups, with base to promote deprotonation when required. Reaction efficiency depends on substrate electronics and steric accessibility, and standard conditions used for alkyl bromide conjugations are generally applicable.