Synthesis
Pyrazole-3-carboxylic acid (1.112 g, 10 mmol) was dissolved in ethanol (50 mL) at 80 °C, followed by slow addition of concentrated sulfuric acid (2 mL). The reaction mixture was kept under stirring for 2 hours. Upon completion of the reaction, ethyl 1H-pyrazole-3-carboxylate (1.350 g, 9.6 mmol, 96% yield) was obtained.
References
[1] Journal of the Iranian Chemical Society, 2016, vol. 13, # 5, p. 823 - 830
[2] Patent: US9206115, 2015, B2. Location in patent: Page/Page column 25-26
[3] Patent: EP3235819, 2017, A1. Location in patent: Paragraph 0264; 0265
[4] Journal of the American Chemical Society, 2000, vol. 122, # 44, p. 10810 - 10820
[5] Patent: WO2008/92942, 2008, A2. Location in patent: Page/Page column 20
