Uses
5-Fluoroindole-2-carboxylic acid,is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and Dyestuff.
Synthesis
General procedure for the synthesis of 5-fluoroindole-2-carboxylic acid from ethyl 5-fluoroindole-2-carboxylate: 103.6 g of ethyl 5-fluoroindole-2-carboxylate was dissolved in a mixed solution consisting of 31.25 g of 96% sodium hydroxide, 183 mL of methanol, and 183 mL of water, and heated at reflux for 1 hour. After the reaction was completed, the reaction solution was cooled to 50 °C, and the pH was adjusted to 3-4 by slowly adding 10% hydrochloric acid solution dropwise.After the reaction solution was completely cooled, the precipitate was collected by filtration to obtain 84.7 g of off-white 5-fluoroindole-2-carboxylic acid in 95% yield, which was shown to contain ≥96% by HPLC analysis.
References
[1] Patent: CN104402795, 2017, B. Location in patent: Paragraph 0040; 0043
[2] Advanced Synthesis and Catalysis, 2016, vol. 358, # 24, p. 3938 - 3942
[3] European Journal of Medicinal Chemistry, 2011, vol. 46, # 7, p. 3149 - 3157
[4] Hoppe-Seyler's Zeitschrift fuer Physiologische Chemie, 1954, vol. 297, p. 229,233
[5] Journal of the Chemical Society, 1955, p. 1283,1284
