2,4-Difluorophenylhydrazine hydrochloride → HCID 118432155, compound

Participants

Reaction Conditions

Reaction Steps

4-(4-Bromo-phenyl)-2-oxo-3-butenoic acid methyl ester (50.0 g, 185.8 mmol) prepared in Step 2 of Preparation 17 and 2,4-difluorophenylhydrazine hydrochloride (36.9 g, 204.4 mmol) were added to acetic acid (600.0 mL). The reaction mixture was stirred at 125° C. for 3 hours, concentrated under reduced pressure, and then ethyl acetate was added thereto. The reaction mixture was washed with a saturated solution of sodium hydrogen carbonate, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure to give 73.4 g of 5-(4-bromo-phenyl)-1-(2,4-difluoro-phenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid methyl ester as a yellow liquid.

Provenance & Evidence