反应详情

In 65 ml. of isopropanol are suspended 4.48 g. of 1,3-dimethyl-5-pyrazolone and 3 g. of calcium hydroxide and the resulting suspension is heated under reflux for 30 minutes with stirring. After cooling, 8.4 g. of 2,4-dichlorobenzoyl chloride is added dropwise thereto. After completion of the dropwise addition, the mixture is heated under reflux for 2 hours. The solvent is distilled off from the reaction mixture and 15 ml. of water is added to the residue. The mixture is made acidic with 23 ml. of a 2 N hydrochloric acid solution and extracted with 60 ml. of chloroform. The chloroform layer is washed with water and the organic phase is separated and dried. The chloroform is distilled off. The residue is recrystallized from ethanol to give 7.6 g. of the desired product as colorless prisms of mp. 165°-166° C. Yield 66.7%

1. temperatureunder reflux for 30 minutes
2. temperatureAfter cooling
3. additionAfter completion of the dropwise addition
4. temperaturethe mixture is heated
5. temperatureunder reflux for 2 hours
6. distillationThe solvent is distilled off from the reaction mixture and 15 ml
7. additionof water is added to the residue
8. extractionof a 2 N hydrochloric acid solution and extracted with 60 ml
9. washThe chloroform layer is washed with water
10. customthe organic phase is separated
11. customdried
12. distillationThe chloroform is distilled off
13. customThe residue is recrystallized from ethanol
14. customto give 7.6 g