Boc-NH-PEG3-CH2COOH is a building block.1,2 It has been used as a linker in the synthesis of proteolysis-targeting chimeras (PROTACs) targeting MEK.1 It has also been used as a spacer in the synthesis of radiolabeled probes for dual labeling of tumor integrin αVβ3 and the gastrin-releasing peptide receptor (GRPR) in tumor tissue in vivo.2
1.Vollmer, S., Cunoosamy, D., Lv, H., et al.Design, synthesis, and biological evaluation of MEK PROTACsJ. Med. Chem.63(1)157-162(2020) 2.Liu, Z., Yan, Y., Chin, F.T., et al.Dual integrin and gastrin-releasing peptide receptor targeted tumor imaging using 18F-labeled PEGylated RGD-bombesin heterodimer 18F-FB-PEG3-Glu-RGD-BBNJ. Med. Chem.52(2)425-432(2009)