Water → 1-Methyl-3,5-diphenylpyrazole

Participants

Reaction Conditions

Reaction Steps

Five parts of 3,5-diphenylpyrazole are dissolved in 25 parts (by volume) of methyl isobutyl ketone. Solid anhydrous sodium hydroxide (1.1 parts) is added and the mixture is heated to 90° C. Dimethyl sulfate (3.43 parts) is added and the mixture is next heated to 112° to 115° C. The reaction mixture is sampled after 1.5 hours, and no unreacted 3,5-diphenylpyrazole is found to be present. The reaction mixture is cooled to 50° C., and 30 parts of water are added. The pH is next adjusted to between 11 and 12 by the addition of aqueous sodium hydroxide. The organic layer is washed twice with 30 parts water. For yield determination the methyl isobutyl ketone is removed in vacuo, producing 4.95 parts (93% crude yield) of an oil which crystallizes on cooling (melting point 52° to 53° C). Analysis of the product shows it to be 85.5% pure as 1-methyl-3,5-diphenylpyrazole.

Provenance & Evidence