Synthesis
The general procedure for the synthesis of isopropyl 3-amino-2-butenoate from isopropyl acetoacetate was as follows: 2.0 g (~20.83 mmol) of isopropyl acetoacetate was accurately weighed and dissolved in 15 mL of anhydrous ethanol. Subsequently, 1.6 g of ammonium acetate was added and the reaction mixture was heated to reflux at 90°C in an oil bath. The reaction progress was monitored by thin layer chromatography (TLC). After 24 hours of reaction, the heating was stopped and the reaction mixture was evaporated to dryness at low temperature. Finally, the reaction solution was distilled under reduced pressure to afford the target compound isopropyl 3-amino-2-butenoate (compound Sf) in 100% yield.
References
[1] Patent: CN102464608, 2016, B. Location in patent: Paragraph 0153; 0154
[2] Patent: CN108101798, 2018, A. Location in patent: Paragraph 0022; 0024; 0026; 0028; 0030-0032; 0034; 0036
[3] Patent: CN105461691, 2016, A. Location in patent: Paragraph 0016
[4] Chemical and Pharmaceutical Bulletin, 1979, vol. 27, # 6, p. 1426 - 1440
[5] Chemical and Pharmaceutical Bulletin, 1989, vol. 37, # 8, p. 2117 - 2121
