Synthesis
Ethanol was placed in a reaction flask at 0°C and stirred, thionyl chloride was added slowly and dropwise, and stirring was maintained until the temperature of the reaction mixture was raised to room temperature (about 30 min). Subsequently, iminodiacetic acid (3.33 g, 25 mmol) was added to the reaction system and the temperature of the reaction was raised to reflux and the reaction was continued overnight. Upon completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched with saturated sodium bicarbonate solution (20 mL) and the pH was adjusted to neutral by adding solid sodium bicarbonate. After distillation under reduced pressure to remove most of the ethanol, the mixture was extracted three times with ethyl acetate (3 x 20 mL). The organic phases were combined, washed once with brine, dried through magnesium sulfate and filtered. Finally, the target product diethyl iminodiacetate (4.15 g, 88% yield) was obtained by distillation under reduced pressure (recovery of organic solvent).
References
[1] Journal of Organic Chemistry, 1988, vol. 53, # 9, p. 1966 - 1969
[2] Journal of the American Chemical Society, 2000, vol. 122, # 26, p. 6169 - 6174
[3] Patent: CN105949080, 2016, A. Location in patent: Paragraph 0018
[4] Tetrahedron Letters, 2008, vol. 49, # 36, p. 5293 - 5296
[5] Helvetica Chimica Acta, 1993, vol. 76, # 2, p. 893 - 899
