反应详情

In a mixture of 20 ml. of dry benzene and 0.28 g. of triethylamine is dissolved 0.72 g. of 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole and then 0.26 g. of methyl chlorocarbonate is added dropwise at room temperature with stirring. After completion of the dropwise addition, the mixture is stirred at room temperature for 1 hour. After completion of the reaction, the reaction mixture is allowed to stand for 12 hours and then 30 ml. of water is added thereto. Then, a benzene layer is separated and an aqueous layer is extracted with benzene. The benzene layer and the benzene extract are combined and the mixture is washed with water and dried over anhydrous sodium sulfate. Then, the solvent is distilled off from the benzene solution and the resulting residue is recrystallized from a small amount of n-hexane to give 0.77 g. of the desired product as white crystals melting at 86°-88° C. Yield 92%.

1. additionIn a mixture of 20 ml
2. additionAfter completion of the dropwise addition
3. stirringthe mixture is stirred at room temperature for 1 hour
4. customAfter completion of the reaction
5. customThen, a benzene layer is separated
6. extractionan aqueous layer is extracted with benzene
7. extractionThe benzene layer and the benzene extract
8. washthe mixture is washed with water
9. dry with materialdried over anhydrous sodium sulfate
10. distillationThen, the solvent is distilled off from the benzene solution
11. customthe resulting residue is recrystallized from a small amount of n-hexane
12. customto give 0.77 g