methyl trimethoxyacetate

67-56-1

17640-25-4

18370-95-1

Methyl 2,2-dichloro-2-methoxyacetate (50 g, 248.5 mmol, 1 eq.) was added to a 500 mL round bottom flask. The reaction flask was cooled to 0 °C in an ice bath, followed by the slow addition of anhydrous methanol (34.33 g, 745.7 mmol, 44 mL, 3 eq.) over 5 min with stirring. The reaction mixture was immediately diluted with anhydrous ether (150 mL). Maintaining the reaction temperature at 0 °C, anhydrous pyridine (49.10 g, 621.4 mmol, 50.20 mL, 2.5 eq.) was slowly added through a constant pressure dropping funnel over 1 hour. After addition, the reaction mixture was continued to be stirred rapidly at 0 °C for 30 min. Stirring was stopped and the mixture was allowed to stand at room temperature for 72 h. Long white needle-like crystals were observed to form in the solution. The mixture was filtered through a mesoporous glass filter and the collected solid was washed with ether. The filtrate was concentrated by rotary evaporation under reduced pressure to give a light yellow oil. The oily substance was again cooled to 0 °C in an ice bath and pyrrolidine (25 mL) was added dropwise through a constant pressure dropping funnel under rapid stirring over a period of 20 min, at which time the solution rapidly changed to a yellow-orange color. After addition, the mixture was continued stirring at 0 °C for 30 min. Subsequent decompression distillation was carried out to recover unreacted pyrrolidine and ethanol at 40 Torr and 28 °C, and the final target product, methyl 2,2,2-trimethoxyacetate (44 g, 80% yield), was collected at 2 Torr and 58 °C as a colorless liquid. The product was characterized by NMR (400 MHz, DMSO-d6): δ 3.80 (s, 3H), 3.30 (s, 9H). Mass spectrometry (EI) analysis showed a molecular ion peak (M+) of 145, corresponding to the molecular formula C6H15O5.