23778-52-1

112-60-7

6482-24-2

23778-52-1

The general procedure for the synthesis of pentaethylene glycol monomethyl ether from tetraethylene glycol truncated and 2-bromoethyl methyl ether was as follows: tetraethylene glycol (55 mmol, 10.7 g) was dissolved in 100 mL of tetrahydrofuran (THF), and potassium tert-butoxide (KOtBu, 55 mL, 1.0 M solution in THF) was added to this solution at room temperature. The resulting mixture was stirred at room temperature for 30 min, followed by the slow dropwise addition of 2-bromoethyl methyl ether (55 mmol, 5.17 mL, dissolved in 50 mL THF). The reaction mixture was stirred overnight at room temperature and then extracted with 300 mL of water and 3 x 300 mL of dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate (Na2SO4). The desiccant was removed by filtration and after evaporation of the solvent, the crude product was purified using silica gel column chromatography (eluent ratio CH2Cl2:CH3OH = 60:140:1) to afford pure pentaethylene glycol monomethyl ether (35% yield).1H NMR (CDCl3) δ 3.75-3.42 (m, 20H, OCH2CH2O), 3.39 (s, 3H MeO).