Cinnamoylbenzene → 3,5-diphenyl-4,5-dihydro-1H-pyrazole

Participants

Reaction Steps

There are reacted 12.5 parts of benzalacetophenone and 3.1 parts (by volume) of hydrazine hydrate in methanol to form 3,5-diphenyl-2-pyrazoline. To the latter is added then 5% palladium on carbon catalyst (2 parts) and the reaction mixture is heated at reflux for 1 hour and 20 minutes. The product, 3,5-diphenylpyrazole, is obtained in 97.8% yield.

Provenance & Evidence