Toluene-4-sulfonic acid 4-tert-butoxycarbonylamino-butyl ester

Tos-O-C4-NH-Boc is an alkyl ether-based PROTAC linker can be used in the synthesis of PROTACs, such as BSJ-03-204 [1]. PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein. PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins[1].

[1]. Wang Z, et al. Proteolysis Targeting Chimeras for the Selective Degradation of Mcl-1/Bcl-2 Derived from Nonselective Targ. J Med Chem. 2019 Aug 21.