Synthesis
a) General procedure for the preparation of ethyl 4-(2-cyano-2-ethoxycarbonylvinylamino)benzoate: triethyl orthoformate (33.3 mL, 0.2 mol) was mixed with ethyl cyanoacetate (21.3 mL, 0.2 mol) in acetic acid anhydride (80 mL), and the mixture was heated for 5 hr at 150-160 °C. Upon completion of the reaction, it was cooled to room temperature and the solvent was removed by distillation under reduced pressure to give ethyl 2-cyano-3-ethoxyacrylate as a yellow solid (28.5 g, 84% yield).
References
[1] Patent: US2006/4046, 2006, A1. Location in patent: Page/Page column 35
[2] Patent: WO2014/145986, 2014, A1. Location in patent: Paragraph 0274
[3] Arkivoc, 2017, vol. 2017, # 3, p. 73 - 86
[4] Phosphorus, Sulfur and Silicon and the Related Elements, 2006, vol. 181, # 3, p. 591 - 599
[5] Patent: US2012/277224, 2012, A1. Location in patent: Page/Page column 18
