Hydrochloric Acid → 4-(2,4-difluorophenyl)benzoic Acid

Participants

Reaction Conditions

Reaction Steps

Combine 4-carbomethoxyphenylboronic acid (1.021 g, 5.67 mmol), 1-bromo-2,4-difluorobenzene (1.000 g, 5.181 mmol.), Pd(OAc)2 (0.113 g, 0.50 mmol), triphenylphosphine (0.149 g, 0.505 mmol), and sodium carbonate (1.664 g, 0.568 mmol). Purge the reaction vessel with argon. Add dimethylformamide (20 mL) and water (2.0 mL) with stirring. Place sealed reaction in an 80° C. oil bath and allow to stir for 24 hours. Cool reaction to room temperature, dilute with ethyl acetate, and filter through a short plug of celite with additional ethyl acetate. Wash organics with water, dry over magnesium sulfate, filter, and evaporate. Purification by flash column chromatography yields 2′,4′-difluorobiphenyl-4-carboxylic acid methyl ester as a yellow solid. Dissolve the purified ester in dioxane (5 mL) and add 5M sodium hydroxide (1 mL). Stir vigorously at 50° C. for 15 hours. Upon completion, acidify the reaction with conc. HCl and extract with ethyl acetate. Evaporation of the solvent yields 300 mg (24.7%) of the title compound. MS (m/e): 233.0 (M−).

Provenance & Evidence