Toluene → 4-(acetoxymethyl)-2-[(E)-2-[4-(trifluoromethyl)phenyl]ethenyl]-1,3-oxazole

関与物質

反応条件

反応手順

(E)-3-(4-(Trifluoromethyl)phenyl)-2-propenamide (950 g, 4.42 mol) and 1,3-dichloroacetone (1045 g, 8.23 mol)were added to toluene (4.75 L) and the mixture was subjected to refluxing azeotropic dehydration using a Dean-Stark tube for 8 hours. During the reaction, an azeotropic mixture (2.38 L) was removed. The reaction mixture was concentrated under reduced pressure, and dimethyl sulfoxide (4.75L) and sodium acetate (905 g, 11.0 mol) were added to the residue. The mixture was stirred at 70-80° C. for 3.5 hours. Methanol (4.75 L) was added. After allowing to cool to room temperature and stirring, the mixture was stirred for 1 hour under ice-cooling. The precipitated crystals were collected by filtration, washed with cold-methanol (1.9 L), and dried under reduced pressure to give 4-(acetoxymethyl)-2-[(E)-2-[4-(trifluoromethyl)phenyl]ethenyl]-1,3-oxazole (1560 g, yield 51%).

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