Amino-PEG10-propionic acid

Amino-PEG10-propionic acid, is a polyethylene glycol-based, amine-functionalized spacer incorporating a propionic acid handle. It is designed to support modular assembly of bifunctional degraders by providing aqueous compatibility, conformational flexibility, and orthogonal functional groups for reliable conjugation. Its spacer architecture can help optimize linker length and local presentation of binding motifs in targeted protein degradation workflows. The following sections describe the structure and reactivity considerations in detail below.

Structure: The linker contains a PEG chain providing hydrophilicity and flexible conformational freedom, flanked by an amino group and a carboxylic acid (propionic acid) for chemical coupling. It features ether linkages within the PEG backbone and stable C–N and C–C framework bonds, supporting robust, water-compatible linker behavior.

Reactivity: The amino group enables formation of amide or urea linkages via standard coupling chemistries, while the carboxylic acid supports activation for nucleophilic acyl substitution. Common approaches include carbodiimide-mediated couplings or activated ester strategies, typically using polar aprotic solvents and controlled pH to preserve functional-group integrity. Reaction design should consider selective activation to avoid cross-reactivity with other electrophiles during PROTAC synthesis.