Hydrochloric Acid → beta-Aminobeta-ethoxyacrylic acid ethyl ester

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Reaction Steps

In an oven-dried flask were placed 113.1 g of redistilled ethyl cyanoacetate, 46 g of ethanol (distilled from calcium hydride), and 500 ml of anhydrous diethyl ether. The solution was cooled to 0°, 36.5 g of hydrogen chloride gas were added and the flask was sealed. The mixture was refrigerated for several days until precipitation of white solid was observed. The white precipitate was collected by filtration and immediately resuspended in approximately 300 ml of diethyl ether. The ether-suspension was mixed with 1000 ml of a 40% aqueous solution of potassium carbonate (previously cooled to 0°). The ether layer was separated and placed over 30 g of anhydrous potassium carbonate. The aqueous phase was washed three times with 150 ml portions of diethyl ether. The washings were added to the ether phase over potassium carbonate. The combined ether phase and washings were decanted onto approximately 80 g of fresh anhydrous potassium carbonate. The potassium carbonate was removed by filtration and the ether was removed by evaporation under reduced pressure. The residue was distilled at 0.25 mm hg. The fraction distilling at 60° was collected to yield 85.5 g of ethyl 3-amino-3-ethoxyacrylate, nD25 = 1.4808. The ir and nmr spectra were consistent with the assigned structure.

Provenance & Evidence