Synthesis
General procedure for the synthesis of 1-ethoxycarbonylimidazole from imidazole and ethyl chloroformate: imidazole (3.75 g, 55.0 mmol) was added to the reactor followed by 50 ml of anhydrous ether. The reaction system was cooled to 0 °C and ethyl chloroformate (2.58 ml, 27.0 mmol) was added slowly and dropwise. After stirring the reaction at 0°C for 1 hour, the reaction system was moved to room temperature and continued for 4 hours. After completion of the reaction, the reaction solution was filtered. The filtrate was redissolved in 100 ml of ether and the organic phase was washed with water and subsequently dried with anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure to give the product 1-ethoxycarbonylimidazole (1.28 g, 17% yield) as a colorless liquid.
References
[1] Angewandte Chemie - International Edition, 2012, vol. 51, # 33, p. 8304 - 8308
[2] Organic Letters, 2010, vol. 12, # 20, p. 4572 - 4575
[3] Patent: CN105566347, 2016, A. Location in patent: Paragraph 0033; 0034; 0035
[4] Patent: CN105503932, 2016, A. Location in patent: Paragraph 0045; 0046; 0047
[5] Justus Liebigs Annalen der Chemie, 1957, vol. 609, p. 75,82
