反应详情

5-Acetyloxy-1-(4-t-butylphenyl)-3-methyl-1H-pyrazole (4.21 g, 15.5 mmol) in 1,4-dioxane (150 mL) was stirred with potassium carbonate (2.14 g, 15.5 mmol) at 110° C. for 3.5 hours, and after addition of water (50 mL), the organic solvent was removed by distillation. Then, ethyl acetate, water and 6 M hydrochloric acid were added to adjust the aqueous layer to pH 2, and the aqueous layer and the organic layer were separated. The aqueous layer was extracted with ethyl acetate twice, and the organic layer was combined with the extract, washed with saturated aqueous ammonium chloride three times and with saturated aqueous sodium chloride once and dried over anhydrous sodium sulfate and filtered. The solvent was removed by distillation, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=6/1→3/1→1/1) to give 2.77 g of the desired product (66% yield).

1. customthe organic solvent was removed by distillation
2. additionThen, ethyl acetate, water and 6 M hydrochloric acid were added
3. customthe aqueous layer and the organic layer were separated
4. extractionThe aqueous layer was extracted with ethyl acetate twice
5. washwashed with saturated aqueous ammonium chloride three times and with saturated aqueous sodium chloride once
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. customThe solvent was removed by distillation
9. customthe residue was purified by silica gel column chromatography (hexane/ethyl acetate=6/1→3/1→1/1)