Ethanol, 2,2′-[oxybis(2,1-ethanediyloxy)] bis-, 1,1′-bis(4-methylbenzenesulfonate) (98.7%)

Ethanol, 2,2′-[oxybis(2,1-ethanediyloxy)]bis-, 1,1′-bis(4-methylbenzenesulfonate)

Molecular Formula: C22H30O9S2

CAS#: 37860-51-8

SMILES: O=S(C1=CC=C(C)C=C1)(OCCOCCOCCOCCOS(C2=CC=C(C)C=C2)(=O)=O)=O

MDL#: MFCD00075239

Catalog#: AMTGC539-EM20

Molecular weight: 502.60 g/mol

Appearance: Pale yellow liquid

Purity: 98.7%

Storage: Long-term storage in a fridge at 2-8°C

Solubility: Dichloromethane, Chloroform, Methanol

Other names:

• Tetraethylene glycol ditosylate
• Bis-Tos-PEG4
• Tos-PEG4-Tos
• Tetraethylene glycol bis(p-toluenesulfonate)
• 1,11-Bis(tosyloxy)-3,6,9-trioxaundecane

Fields of Interest

PEG linker synthesis, organic synthesis, medicinal chemistry, chemical biology, bioconjugation reagent development, PROTAC linker development, polymer chemistry, materials science, surface functionalization, molecular crosslinking, specialty chemical synthesis

Background

Tetraethylene glycol ditosylate (CAS 37860-51-8) is a homobifunctional PEG derivative consisting of a flexible tetraethylene glycol (PEG4) spacer terminated at both ends with tosylate (p-toluenesulfonate) groups. The oligoethylene glycol backbone provides molecular flexibility and hydrophilic character, while the two terminal tosylates serve as effective leaving groups for nucleophilic substitution.

Unlike azide- or alkyne-functionalized PEGs that participate directly in click chemistry, Tetraethylene glycol ditosylate is primarily valuable as a synthetic intermediate for preparing other functionalized PEG linkers. Its two activated termini can be displaced by suitable nucleophiles, providing a versatile route to symmetrical bifunctional PEG derivatives and more complex molecular architectures.

Applications

Tetraethylene glycol ditosylate is useful in PEG linker synthesis, organic synthesis, medicinal chemistry, materials science, polymer modification, and bioconjugation reagent development. The terminal tosylate groups provide convenient sites for nucleophilic substitution, enabling the preparation of PEG derivatives containing azide, amine, thiol, halide, and other functional groups.

Because both ends of the PEG chain are activated, the compound can also serve as a precursor for bifunctional crosslinkers and symmetrical molecular constructs. This makes it particularly useful in multistep synthesis where a defined PEG4 spacer is needed to introduce controlled molecular separation while retaining the ability to install application-specific terminal functionalities.

Literature:

• Organic Letters, 2002, vol. 4, # 14, p. 2329 – 2332
• Zhurnal Organicheskoi Khimii, 1990, vol. 26, # 11, p. 2425 – 2433
• Chemical Communications, 2025, vol. 61, # 14, p. 3001 – 3004