Lemon Juice Catalysis and Mechanical Grinding Yield Pyrazole-Coumarin Compounds at 90% to 92%
A study published November 14 in Scientific Reports presents a green method for synthesizing pyrazole-coumarin compounds using lemon juice as a catalyst and mechanical grinding. The author is Anhar Abdel-Aziem of Cairo University. Fresh lemon juice contains 5 to 7 percent citric acid; in the experiments, 10 milliliters of lemon juice were boiled for about 10 minutes and the precipitate was used.
The intermediate compounds 4 and 5 were each obtained in 92 percent yield, with atom economies of 96.5 percent and 95.9 percent respectively. Compared with the one to two hours required by conventional methods, mechanical grinding completed the reaction in 5 to 10 minutes, and final product yields were 90 to 92 percent.
For compound 7a, the atom economy was 77.78 percent and the E-factor was 0.397.
Source: Scientific
Published by GSM · USA (original Chinese edition)
Photo: 图：结在柠檬树上的柠檬果实。来源：Bj.schoenmakers，Wikimedia Commons，CC0 1.0。 / Photo: Lemons growing on a lemon tree. Source: Bj.schoenmakers, Wikimedia Commons, CC0 1.0.
