Description

Peg21-Tos CAS NO 2179113-08-5 is a high-purity, monodisperse polyethylene glycol (PEG) derivative functionalized with a tosylate (p-toluenesulfonate) group at one terminus. This reactive intermediate is critical for the controlled, site-specific conjugation of PEG chains to target molecules, enhancing their solubility, stability, and pharmacokinetic profiles. It is an essential building block for researchers and manufacturers in the pharmaceutical, bioconjugation, and advanced materials sectors who require precise and reliable PEGylation reagents.

Application

• Pharmaceutical PEGylation: A key reagent for attaching PEG chains to therapeutic proteins, peptides, and oligonucleotides to reduce immunogenicity, increase circulation half-life, and improve stability.
• Bioconjugation & Linker Chemistry: Serves as a versatile heterobifunctional linker for creating PEG-based cross-linkers or conjugating biomolecules to surfaces, nanoparticles, or other polymers.
• Drug Delivery System Development: Used in the synthesis of PEGylated liposomes, dendrimers, and polymeric micelles for targeted and controlled drug release.
• Diagnostic Reagent Synthesis: Employed to modify antibodies, enzymes, or other detection molecules with PEG to reduce non-specific binding and improve assay performance.
• Surface Functionalization: Applied to modify material surfaces (e.g., gold nanoparticles, quantum dots, medical devices) with a reactive PEG layer to impart stealth properties and biocompatibility.
• Polymer Chemistry & Material Science: Acts as a macro-initiator or monomer for the synthesis of well-defined block copolymers and functional hydrogels.

Basic Information

Product Name	Peg21-Tos
CAS No.	2179113-08-5
Molecular Formula	Contact for details
Molecular Weight	~1100 g/mol (Contact for exact value)
Synonyms	mPEG21-Tosylate; Monomethoxy Polyethylene Glycol 21 Tosylate; PEG 1000 Monomethyl Ether Tosylate; α-Methoxy-ω-tosyl-poly(ethylene glycol); mPEG-OTs (n~21); Poly(oxy-1,2-ethanediyl), α-methoxy-ω-[(4-methylphenyl)sulfonyl]-; 2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-[2-Methoxyethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethyl 4-methylbenzenesulfonate
EINECS	Contact for details

Quality Control

Our Peg21-Tos is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure high purity, consistent molecular weight, and functional group integrity, meeting the stringent requirements for pharmaceutical R&D and process development. Certificates of Analysis (COA) detailing purity (by HPLC/NMR), degree of functionalization, and residual solvent levels are provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 2-8°C under an inert atmosphere (e.g., nitrogen or argon) for long-term stability. Allow the sealed container to equilibrate to room temperature before opening to prevent moisture condensation. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	White to off-white waxy solid or viscous liquid
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Molecular Weight (SEC/MALS)	1100 ± 50 g/mol
Degree of Tosylation (NMR)	≥ 90%
Methoxy Group Content	Conforms
Water Content (KF)	≤ 1.0%
Residual Solvents (GC)	Meets ICH guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.