反应详情

43.60 g (0.13 mol) of 2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoyl chloride in 375 ml of anhydrous dioxane and 13.56 g (0.134 mol) of triethylamine in 375 ml of anhydrous dioxane are simultanouesly added dropwise at room temperature under a protective gas atmosphere to a solution 12.74 g (0.13 mol) of 5-hydroxy-1-methylpyrazole and 300 ml of anhydrous dioxane. After the reaction mixture had been stirred for 2 hours at room temperature, it was filtered through silica gel and the residue was washed with dioxane. The eluate was concentrated in vacuo to approximately 500 ml, and 17.94 by(0.13 mol) of dried, finely powdered potassium carbonate were added. After the mixture had been refluxed for 6 hours, the solvent was distilled off in vacuo and the residue was taken up in approximately 700 ml of water. Insoluble constituents were filtered off, and the pH of the filtrate was brought to 2-3 by slow addition of 10% strength hydrochloric acid. The precipitate which formed was filtered off with suction. This gave 46.16 g (92% of theory) of 4-[2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoyl]-5-hydroxy-1-methyl-1H-pyrazole.

1. filtrationit was filtered through silica gel
2. washthe residue was washed with dioxane
3. concentrationThe eluate was concentrated in vacuo to approximately 500 ml, and 17.94 by(0.13 mol)
4. customof dried
5. additionfinely powdered potassium carbonate were added
6. temperatureAfter the mixture had been refluxed for 6 hours
7. distillationthe solvent was distilled off in vacuo
8. filtrationInsoluble constituents were filtered off
9. additionthe pH of the filtrate was brought to 2-3 by slow addition of 10% strength hydrochloric acid
10. customThe precipitate which formed
11. filtrationwas filtered off with suction