Hydrochloric Acid → 4-(1-Imidazolyl)benzoic Acid

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Reaction Steps

Combine methyl 4-fluorobenzoate (1.52 g, 10 mmol), 1H-imidazole (0.82g, 12 mmol) and potassium carbonate (1.40 g, 10 mmol) in dimethylsulfoxide (7 mL) and heat the mixture with stirring at 120°-130° C. for 5 hours, cool, add water and acid, extract with ether. Adjust the pH of the aqueous layer to 8 with sodium carbonate, extract with ether, dry the extract with sodium sulfate and evaporate. 4-(1H-Imidazol -1-yl)benzoic acid is prepared by refluxing this methyl ester (0.61 g, 3 mmol) in 5 mL of 10% aqueous sodium hydroxide for five minutes; cool, neutralize to pH 6-7 with hydrochloric acid, filter and dry the precipitated acid.

Provenance & Evidence