Ethylene Glycol → Glycol monostearate

Beteiligte Stoffe

Reaktionsschritte

A solution of stearic anhydride (1.14 g, 2.06 mmol) in dichloromethane (30 mL) was cannulated into a stirred solution of ethylene glycol (1.10 mL, 19.7 mmol), DMAP (22 mg, 0.18 mmol) and triethylamine (0.300 mL, 2.16 mmol) in dichloromethane (20 mL). After stirring for 90 min. the reaction was quenched with the addition of H2O (100 mL). After separation of the phases the aqueous fraction was re-extracted with dichloromethane (2×50 mL) and the combined organic extract was washed with brine (70 mL). After drying (MgSO4) and filtration the solvent was removed at reduced pressure to give the crude product that was purified by chromatography on silica gel. Gradient elution with ethyl acetate/petroleum ether (10:90→30:70) afforded the title compound 48 (265 mg, 0.807 mmol, 39%) as an oil; 1H NMR (300 MHz, CDCl3) δ 4.25-4.20 (m, 2H), 3.83-3.78 (m, 2H), 2.38 (t, 2H, J 7.5 Hz), 2.00-1.97 (m, 1H), 1.62-1.55 (m, 2H), 1.35-1.20 (m, 28H), 0.87-0.81 (m, 3H); 13C NMR (75 MHz, CDCl3) δ 174.6, 66.3, 61.7, 34.6, 32.3, 30.1, 29.8, 29.7, 29.6, 29.5, 25.3, 23.1, 14.5; HRMS-ESI (+ve) (Found: m/z 346.3323 (MNH4+). C20H44NO3 requires m/z 346.3316).

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