Name: COOH-PEG5-COOtBu
Brand: BOC Sciences
Rating: 5 (1 reviews)

Size

Price

Stock

Quantity

$--

In stock

Purity

≥95%

Solubility

Soluble in DCM, DMF, DMSO, Water

Appearance

Pale Yellow or Colorless Oily Matter

Storage

Store at 2-8°C

Shipping

Room temperature in continental US; may vary elsewhere.

IUPACName

3-[2-[2-[2-[2-[3-[(2-methylpropan-2-yl)oxy]-3-oxopropoxy]ethoxy]ethoxy]ethoxy]ethoxy]propanoic acid

Synonyms

Acid-PEG5-t-butyl ester; Acid-PEG5-C2-Boc; HOOCCH2CH2O-PEG4-CH2CH2COOtBu; COOH-PEG5-OtBu; Carboxy-PEG5-t-butyl ester; 2,2-Dimethyl-4-oxo-3,7,10,13,16,19-hexaoxadocosan-22-oic acid; 4,7,10,13,16-Pentaoxanonadecanedioic acid, 1-(1,1-dimethylethyl) ester; 4,7,10,13,16-Pentaoxanonadecane-1,19-dioic acid, mono(1,1-dimethylethyl) ester

Boiling Point

495.2±45.0°C (Predicted)

Density

1.109±0.06 g/cm3 (Predicted)

InChI Key

ILIIUHKWCBCCNI-UHFFFAOYSA-N

InChI

InChI=1S/C18H34O9/c1-18(2,3)27-17(21)5-7-23-9-11-25-13-15-26-14-12-24-10-8-22-6-4-16(19)20/h4-15H2,1-3H3,(H,19,20)

SMILES

CC(C)(C)OC(=O)CCOCCOCCOCCOCCOCCC(=O)O

COOH-PEG5-COOtBu is a PEG-based bifunctional linker designed to support PROTAC assembly by providing two complementary functional handles for controlled conjugation. Its flexible ethylene glycol scaffold can help tune linker length, solvation, and the spatial presentation of ligands, which are key factors for efficient ternary-complex formation. The protected carboxylate functionality enables stepwise synthesis, allowing researchers to construct targeted protein degraders with reproducible linker architectures.

Structure: The linker contains a poly(ethylene glycol) chain featuring ether linkages that confer conformational flexibility and hydrophilicity. It bears two carboxyl-derived termini, one presented as a free acid and the other as a tert-butyl-protected carboxylate, enabling orthogonal functionalization without premature cross-reactivity.

Reactivity: Suitable PROTAC conjugation strategies typically involve converting the free carboxylic acid to an activated ester or amide-forming intermediate, then coupling to ligand-bearing nucleophiles under standard peptide-coupling conditions. The tert-butyl-protected carboxylate can be selectively deprotected using acid to restore a carboxylic acid, followed by sequential activation for orthogonal attachment. Common approaches use coupling reagents and compatible polar solvents, with mild bases to maintain linker integrity.

Stock concentration: *

Desired final volume: *

Desired concentration: *

* Our calculator is based on the following equation:
Concentration (start) x Volume (start) = Concentration (final) x Volume (final)
It is commonly abbreviated as: C₁V₁ = C₂V₂