217817-01-1

Tos-PEG4-t-butyl ester is a PEG linker containing a t-butyl ester and a tosyl group. The hydrophilic PEG spacer increases solubility in aqueous media. The t-butyl protected carboxyl group can be deprotected under acidic conditions. The tosyl group is a very good leaving group for nucleophilic substitution reactions.

Tos-PEG4-t-butyl ester (Tos-PEG4-Boc) is a PROTAC linker, which refers to the PEG composition. Tos-PEG4-t-butyl ester (Tos-PEG4-Boc) can be used in the synthesis of a series of PROTACs, such as BI-3663 (HY-111546). BI-3663 is a highly selective PTK2/FAK PROTAC, with cereblon ligands to hijack E3 ligases for PTK2 degradation, and inhibits PTK2 with an IC50 of 18 nM[1].

PEGs; Alkyl/ether

[1] Popow J, et al. Highly Selective PTK2 Proteolysis Targeting Chimeras to Probe Focal Adhesion Kinase Scaffolding Functions. J Med Chem. 2019 Mar 14;62(5):2508-2520. DOI:10.1021/acs.jmedchem.8b01826