Uses
Coumalic acid undergoes thermal reaction with 1,3-butadiene to yield dimethyl tricycle[3.2.1.02,7]oct-3-ene-2,4-dicarboxylate.
Synthesis
The general procedure for the synthesis of coumaric acid from DL-malic acid was as follows: fuming sulfuric acid (287 g) was slowly added dropwise over a period of 2 hours to a suspension of DL-malic acid (200 g) dissolved in concentrated sulfuric acid (313 g) at 75 °C. After the dropwise addition was completed, the reaction mixture was continued to be stirred at the same temperature for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently poured slowly into ice water over a period of 1 hour. After stirring for 15 minutes, the mixture was left to stand overnight. On the following day, the mixture was cooled to below 10°C and the coumaric acid crude product was isolated by filtration. After washing and drying, coumaric acid was obtained (71 g, 95% purity, 65% yield).
References
[1] Liebigs Annalen der Chemie, 1990, p. 233 - 238
[2] Journal of Heterocyclic Chemistry, 2008, vol. 45, # 1, p. 229 - 234
[3] Patent: WO2004/792, 2003, A1. Location in patent: Page 15
[4] Organic Process Research and Development, 2003, vol. 7, # 1, p. 74 - 81
[5] Patent: CN103788039, 2016, B. Location in patent: Paragraph 0039; 0041-0044
