Sodium hydride → 3-Fluoro-alpha-(4-fluorophenyl)-benzenepropanoic acid

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Reaction Steps

To a solution of 10.8 g of 60% sodium hydride in 400 mL of tetrahydrofuran was added 44.7 g of methyl 4-fluorophenylacetate dropwise. Then, 50 g of 3-fluorobenzyl bromide was added dropwise. The mixture was then heated to reflux for approximately 18 hours. After this time, the reaction was cooled to room temperature and filtered. The filtrate was partitioned between ether and 5% aqueous sodium bicarbonate, and the ether extracts were dried over magnesium sulfate and concentrated to 77.57 g of a yellow oil. The crude product was combined with 275 mL of methanol, 20 mL of 50% aqueous NaOH and 50 mL of H2O and the mixture was refluxed for about 18 hours. The reaction was then cooled to room temperature, concentrated and partitioned between water and ether. The aqueous extracts were made acidic with concentrated HCl and extracted with ether. The ether extracts were dried over MgSO4, filtered, concentrated and the crude product was triturated with hexane to afford 43.62 g of a white solid; mp 92°-94° C.

Provenance & Evidence