反应详情

A mixture of 0.3 g. of 5-chloro-4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazole, 2.1 g. of sodium hydrogen sulfide 2 hydrate and 6 ml. of ethanol is heated under reflux on a water bath for 3 hours. After completion of the reaction, the ethanol is distilled off under reduced pressure from the reaction mixture and 15 ml. of water is added followed by extraction with benzene. To an aqueous layer is added conc. hydrochloric acid to adjust the pH to 1 and the mixture is extracted with chloroform. The extract is washed with water and then dried over anhydrous sodium sulfate. The solvent is distilled off from the extract to give the crude crystalline substance, which is then recrystallized from n-hexane to give 0.10 g. of the desired product as yellow powders having a melting point of 85°-86° C. Yield 33.3%.

1. additionA mixture of 0.3 g
2. temperatureunder reflux on a water bath for 3 hours
3. customAfter completion of the reaction
4. distillationthe ethanol is distilled off under reduced pressure from the reaction mixture and 15 ml
5. additionof water is added
6. extractionfollowed by extraction with benzene
7. additionTo an aqueous layer is added conc. hydrochloric acid
8. extractionthe mixture is extracted with chloroform
9. washThe extract is washed with water
10. dry with materialdried over anhydrous sodium sulfate
11. distillationThe solvent is distilled off from the
12. extractionextract
13. customto give the crude crystalline substance, which
14. customis then recrystallized from n-hexane
15. customto give 0.10 g