反应详情

14.25 g (50 mmoles) of 2-[3-chloro-4-(4-chloropyrazol-1-yl)phenyl]propionic acid, 150 ml of ethanol and 7 g of concentrated sulfuric acid are heated to the boil for 10 hours. Concentration is effected, followed by pouring onto ice water, extracting with diethyl ether, washing of the organic solution with sodium hydrogen carbonate solution, drying the organic solution and distilling it to obtain 12.4 g (83% of theory) of 2-[3-chloro-4-(4-chloropyrazol-1-yl)phenyl]propionic acid ethyl ester (b.p. 134° C./3·10-2 mm Hg).

1. concentrationConcentration
2. additionby pouring onto ice water
3. extractionextracting with diethyl ether
4. washwashing of the organic solution with sodium hydrogen carbonate solution
5. customdrying the organic solution
6. distillationdistilling it