Chemoselectivity in the reactions between ethyl 4,4,4-trifluoro-3-oxobutanoate and anilines: Improved synthesis of 2-trifluoromethyl-4-and 4-trifluoromethyl-2-quinolinones

摘要

Chemoselectivity in the reactions between ethyl 4,4,4-trifluoroacetoacetate (ethyl 4,4,4-trifluoro-3-oxobutanoate) and various anilines was systematically studied as a function of the reaction conditions used (solvent/temperature, catalyst). The results obtained allowed chemoselective (>90%) synthesis of the corresponding ethyl 3-arylamino-4,4,4-trifluorobut-2-enoates and N-aryl-4,4,4-trifluoro-3-oxobutyramides, which were cyclized to afford 2-trifluoromethyl-4-quinolinones and 4-trifluoromethyl-2-quinolinones, respectively. [References: 18]