Methanol → 2,5-bis(2-fluorophenyl)-4-hydrazinylidenepyrazol-3-one

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Reaction Steps

4-Diazo-2,5-bis(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one [(Example 18, Step 2) 213 mg, 0.714 mmol] was dissolved in acetonitrile (10 mL) and treated with triphenylphosphine (225 mg, 0.857 mmol, 1.2 equiv). After stirring for 30 minutes at ambient temperature, the mixture was treated with methanol (5 mL) and water (5 mL) and warmed to 60° C. for 1 hour. The mixture was cooled to ambient temperature, poured into brine (50 mL) and sodium bicarbonate (20 mL, aqueous saturated) and extracted with ethyl acetate (2×100 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 70:30; hexanes:ethyl acetate), providing the titled compound.

Provenance & Evidence