2,4-Difluorophenylhydrazine hydrochloride → HCID 118431621, compound

Participants

Reaction Conditions

Reaction Steps

4-(5-Bromo-thiophen-2-yl)-2-oxo-3-butenoic acid methyl ester (17.0 g, 61.8 mmol) prepared in Step 2 and 2,4-difluorophenylhydrazine hydrochloride (12.3 g, 68.0 mmol) were added to acetic acid (200.0 mL). The reaction mixture was stirred at 125° C. for 2 hours, concentrated under reduced pressure, and then ethyl acetate was added thereto. The mixture was washed with a saturated solution of sodium hydrogen carbonate, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure to give a yellow liquid residue. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/20) to give 15.1 g of the titled compound as a yellow solid.

Provenance & Evidence