Hydrochloric Acid → 3-(4-Methoxyphenoxy)benzoic acid

Participants

Reaction Steps

Ethyl 3-hydroxybenzoate (34.0 grams (g), 0.205 mole) (Aldrich Chemical Company, Milwaukee, Wis.), 4-bromoanisole (26.0 milliliters (ml)), (38.8 g, 0.208 mole) (Aldrich Chemical Company), anhydrous potassium carbonate (17.8 g, 0.129 mole) and copper powder (10.0 g, 0.157 mole), (Fisher Scientific, Pittsburgh, Pa.) were heated under nitrogen to 190° C. with slow stirring. Water generated during the reaction was removed by means of a short-path distillation apparatus attached to the reaction flask. After 20 hours, the reaction mixture was allowed to cool and 20 percent aqueous sodium hydroxide (NaOH) (50 ml) was added. Ester hydrolysis was complete after 1 hour at reflux. The cooled reaction mixture was acidified with concentrated hydrogen chloride (HCl), partitioned between methylene chloride (CH2Cl2 (300 ml)) and water (50 ml), and filtered to remove copper powder. The phases were separated and the organic layer was washed with saturated sodium chloride (NaCl) (2×100 ml), dried with magnesium sulfate (MgSO4), filtered, and solvent evaporated to afford a light brown solid. The crude product was recrystallized from 60 percent aqueous acetic acid to afford 3-(4'-methoxyphenoxy)benzoic acid as off-white crystals (40.77 g, 0.167 mol) with a melting point (m.p.) of 120° C. to 125° C.

Provenance & Evidence