(2e)-3-(Trimethylazaniumyl)prop-2-enoate

synthetischePreparative Methods of (E)-(Carboxyvinyl)trimethylammonium Betaine: A mixture of 25.0 g of ethyl propiolate, 14 mL of dichloromethane, and 440 mL of water is cooled to 5 °C and 90 mL of an aqueous 25% solution of trimethylamine is added with vigorous stirring over a period of 30 min. The mixture is then warmed to 25 °C for 3 h. The aqueous layer is separated and washed three times with 100 mL of dichloromethane. The aqueous solution is concentrated in vacuo at 45 °C. When the residue gives the appearance of a wet solid, it is treated with 150 mL of dioxane and concentrated as described above. The dioxane treatment-concentration procedure is repeated three times. The resulting yellow solid is triturated with acetonitrile until a white solid is obtained (25 g, 76% yield).