Lithium Hydroxide → 4-(2,4,6-Trimethylphenyl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

Combine 1-iodo-2,4,6-trimetbylbenzene (2.966 g, 12.05 mmol), 4-carboxyphenylboronic acid (1.0 g, 6.026 mmol), Pd(OAc)2 (0.0067 g, 0.005 mmol), tetrabutylammonium bromide (0.388 g, 1.2055 mmol), and potassium phosphate (2.557 g, 12.05 mmol). Purge the reaction vessel with argon and add anhydrous DMF (20 ml) to the reaction mixture. Beat the sealed reaction vessel to 120° C. with stirring until completion as determined by TLC. Cool reaction mixture to room temperature. Add methyl iodide (1.0 ml, 36.63 mmol) to reaction mixture with continued stirring until completion. Dilute the reaction with ethyl acetate and filter though a short plug of celite with additional ethyl acetate. Wash the organics with water, dry over MgSO4, filter and evaporate. Purification by flash column chromatography yields 2′,4′,6′-trimethylbiphenyl-4-carboxylic acid methyl ester as a yellow solid. Dissolve the purified ester in dioxane (45 ml) and water (5 ml) containing 5 eq of LiOH with stirring at 60° C. Upon completion, evaporate the solvent, acidify the reaction mixture with hydrochloric acid, and extract with ethyl acetate. Dry the organics over MgSO4, filter, and evaporate to yield 0.023 g (16%) of the title compound. MS (m/e): 239.1 (M−).

Provenance & Evidence