Chloromethyl Methyl Ether → N-methoxymethyl-N-methylpyrrolidinium chloride

Participants

Reaction Conditions

Reaction Steps

A 30.0 g quantity of N-methylpyrrolidine (reagent, product of Tokyo Kasei Co., Ltd.) was dissolved in 120 g of methyl acetate, followed by replacement with nitrogen. A 31.2 g quantity of chloromethyl methyl ether (reagent, product of Tokyo Kasei Co., Ltd.) was added dropwise to the solution at 5° C. over a period of 1 hour. The mixture was stirred at 5° C. for 1 hour, the temperature was slowly raised, and the mixture was stirred at room temperature for 10 hours to complete the reaction. The reaction mixture was filtered, and the solid product was washed with 150 g of methyl acetate and 150 g of acetone. The washed product was dried in a vacuum, giving 53.7 g of N-methoxymethyl-N-methylpyrrolidinium chloride. To the chloride salt (53.7 g) obtained was added 71.2 g of 42% aqueous solution of HBF4 to dissolve the salt. Nitrogen was bubbled through the solution at 130° C. to remove water, hydrogen chloride and excessive HBF4. To the solution was added 70 ml of methanol, and nitrogen was bubbled through the mixture at 130° C. to further remove water, hydrogen chloride and excessive HBF4 and obtain 68.2 g of the desired electrolyte, i.e., N-methoxymethyl-N-methylpyrrolidinium tetrafluoroborate (water: 30 ppm, methylpyrrolidine tetrafluoroborate: 4000 ppm). To 68.2 g of the electrolyte were added 2.0 g of barium chloride and 70 ml of methanol within a glove box having an argon atmosphere with a dew point of −60° C. Nitrogen was bubbled through the mixture at 130° C. to remove the methanol, followed by filtration with a membrane filter and analysis.

Provenance & Evidence