反应详情

4-[(3-Fluoro-4-methylphenyl)methyl]-1,2-dihydro-5-methyl-3H-pyrazol-3-one (1.00 g) was suspended in N,N-dimethyl-formamide (5 mL) at room temperature. Potassium carbonate (0.376 g) was added to the suspension, and the mixture was stirred for 30 minutes. Acetic anhydride (0.486 g) was added to the reaction mixture in a dropwise manner at room temperature. The mixture was stirred at room temperature overnight and at 50° C. for 2 hours. The mixture was cooled to room temperature under stirring, the mixed solution of glacial acetic acid (0.164 g) and water (5.0 g) was added to the mixture. After confirming the precipitation of the crystals, water (25 g) was added to the mixture. The obtained crystals were collected by filtration and washed with water. The obtained wet crystals were dried under reduced pressure to give a yellowish-white solid of 1-acetyl-4-[(3-fluoro-4-methylphenyl)methyl]-1,2-dihydro-5-methyl-3H-pyrazol-3-one (0.502 g).

1. stirringThe mixture was stirred at room temperature overnight and at 50° C. for 2 hours
2. stirringunder stirring
3. customthe precipitation of the crystals, water (25 g)
4. additionwas added to the mixture
5. filtrationThe obtained crystals were collected by filtration
6. washwashed with water
7. customThe obtained wet crystals were dried under reduced pressure