Methanol → Difenzoquat metilsulfate

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence