Hydrazine hydrate (1:1) → 5-(4-Chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-pyrazole-3-carbohydrazide

Participants

Reaction Steps

20 g of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carbonyl chloride in 100 ml of ethanol are placed under nitrogen and the mixture is heated at reflux for 2 hours. It is allowed to return to a temperature of 20-25° C., then 50 g of hydrazine hydrate are added and the mixture is again heated at reflux for 3 and a half hours. The reaction medium is filtered while hot and then the ethanol is evaporated. The reaction medium is concentrated, then taken up in 150 ml of DCM and separated by settling. The aqueous phase is discarded, the organic phase is washed twice with 100 ml of water and then the DCM is evaporated. After drying under vacuum, 16.9 g of the expected compound are obtained.

Provenance & Evidence