Hydrochloric Acid → 1-Methyl-3,5-diphenylpyrazole

Participants

Reaction Conditions

Reaction Steps

545.0 Grams (2.43 moles) of dibenzoylmethane and 533 ml. of pyridine are stirred together and heated to 80° C. 112 Grams (2.43 moles) of methylhydrazine are then slowly added to the mixture and a strong exothermic reaction ensues necessitating cooling of the mixture with a water bath. When addition is complete, the mixture is heated to reflux and maintained in this condition for 40 minutes. The mixture is then cooled to 30° C., poured into 19 liters of 3N HCl, filtered, and the solid collected. This is reslurried in 198 grams (2.43 moles) of sodium acetate dissolved in 19 liters of water. The mixture is filtered, water washed and air dried to give 535 grams of product, 94.5% yield, having melting point 58° C. to 59° C.

Provenance & Evidence