反应详情

温度

70 °C

46.8 g (0.2 mol) of 1-methyl-3,5-diphenylpyrazole together with 40 g (1.25 mol) of methanol are introduced into the reaction vessel. After 19.4 g (0.19 mol) of 96% strength sulfuric acid have been added, the reaction solution is brought to 160° C. by distilling off methanol. 608 g (19 mol) of methanol are metered in below the surface of the reaction mixture in the course of 7.5 hours. After the mixture has been cooled to 70° C., 25 g of 1,2-dichloroethane are added, and the mixture is cooled to room temperature with stirring. The reaction mixture is filtered and washed with 12.5 g of 1,2-dichloroethane. 67.7 g of 1,2-dimethyl-3,5-diphenylpyrazolium methylsulfate with a content of 97.5% (HPLC) of m.p. 157°-159° C. are obtained, which corresponds to a yield of 91.7% of theory.

1. customis brought to 160° C.
2. distillationby distilling off methanol
3. customare metered in below the surface of the reaction mixture in the course of 7.5 hours
4. temperaturethe mixture is cooled to room temperature
5. filtrationThe reaction mixture is filtered
6. washwashed with 12.5 g of 1,2-dichloroethane