Benzyl-PEG4-alcohol is a PEG linker with an acid labile, benzyl protecting group and a reactive primary alcohol. The primary alcohol can react and further derivatize the compound. The hydrophilic PEG linker increases the water solubility of the compound in aqueous media.
Triethylene glycol (30 g, 0.2 mol) was dissolved in aqueous sodium hydroxide solution (8 g NaOH dissolved in 8 mL H2O) and stirred for 10 minutes. Subsequently, benzyl chloride (7 mL, 0.062 mol) was slowly added to the reaction system, and the reaction mixture was heated to 100 °C and stirred continuously overnight. Upon completion of the reaction, the crude product was diluted with saturated sodium chloride solution (500 mL) and subsequently extracted with dichloromethane (2 x 400 mL). The organic layers were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. Purification by column chromatography (silica gel as stationary phase, eluent ethyl acetate to ethyl acetate/methanol, 10:1, v/v/v) afforded the light yellow oily target product triglyceride monobenzyl ether (9.87 g, 67% yield).
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