(2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethyl)-carbamic acid tert-butyl ester

Description

N-Boc-PEG3-alcohol is a PEG linker containing a hydroxyl group and Boc-protected amino group. The hydrophilic PEG spacer increases solubility in aqueous media. The hydroxyl group enables further derivatization or replacement with other reactive functional groups. The Boc group can be deprotected under mild acidic conditions to form the free amine.

Chemical Properties

Colourless Oil

Uses

A cross-linking reagent

Synthesis

GENERAL STEPS: Di-tert-butyl dicarbonate (1.75 g, 8.04 mmol) was slowly added to a solution of 2-[2-(2-aminoethoxy)ethoxy]ethanol (600 mg, 4.02 mmol) dissolved in a mixture of methanol/triethylamine (68 mL, 9:1, v/v). The reaction mixture was stirred under reflux conditions. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was separated by extraction with dichloromethane (DCM) and water. The organic layer was dried over anhydrous magnesium sulfate (MgSO4) and subsequently concentrated under reduced pressure to afford tert-butyl (2-(2-(2-hydroxyethoxy)ethoxy)ethyl)carbamate (902 mg, 90% yield). Product characterization: light yellow oil; 1H NMR (400 MHz, CDCl3) δ 3.77-3.71 (m, 2H), 3.66-3.55 (m, 8H), 3.49-3.31 (m, 2H), 1.45 (s, 9H); 13C NMR (100 MHz, CDCl3) δ 156.2, 79.9, 73.0. 70.6, 70.5, 70.0, 61.9, 40.5, 28.6; HRMS (ESI) calculated value C11H24NO5 ([M+H]+) 250.1654, measured value 250.1649.

IC 50

PEGs

References

[1] Helvetica Chimica Acta, 1991, vol. 74, # 8, p. 1697 - 1706
[2] Bioorganic and Medicinal Chemistry, 2012, vol. 20, # 14, p. 4443 - 4450
[3] Tetrahedron, 2011, vol. 67, # 49, p. 9588 - 9594
[4] Journal of Medicinal Chemistry, 2009, vol. 52, # 22, p. 7029 - 7043
[5] Inorganica Chimica Acta, 2011, vol. 365, # 1, p. 38 - 48