Synthesis
Synthesis: To a 250 ml round bottom flask was added p-benzoquinone (11.89 g, 0.11 mol) and 120 ml acetone and stirred well. Subsequently, a solution containing 0.11 mol of ethyl 3-(methylamino)-2-butenoate was added slowly and dropwise. The reaction mixture was stirred at 30°C for 2 hours. After completion of the reaction, the solvent was removed by distillation. The crude product was purified by recrystallization using acetone.
References
[1] Patent: CN106946761, 2017, A. Location in patent: Paragraph 0047-0050
[2] Journal of Organic Chemistry, 1959, vol. 24, p. 1750
[3] Patent: US2852527, 1956,
[4] Zhurnal Obshchei Khimii, 1959, vol. 29, p. 2777,2780; engl. Ausg. S. 2742, 2744
[5] Tetrahedron Letters, 2009, vol. 50, # 28, p. 4182 - 4184