General procedure for the synthesis of 4-phenoxyphenylacetic acid from methyl 2-(4-phenoxyphenyl)acetate: 1N aqueous NaOH solution (7.8 mL) was added to a solution of methyl 4-phenoxyphenylacetate (948 mg, 3.9 mmol) in ethanol (20 mL), and the reaction was stirred at room temperature for 5 hours. After completion of the reaction, the reaction solution was concentrated under reduced pressure and acidified by adding 1N aqueous hydrochloric acid (10 mL). The precipitated white solid was collected by filtration and washed with water and ether sequentially to afford 4-phenoxyphenylacetic acid (813 mg, 91% yield) as a white solid. The product was detected by LC-MS showing m/z 229 [M + H]+, and 1H-NMR (300 MHz, CDCl3) data were as follows: δ 6.91-7.01 (m, 4H), 7.10-7.14 (t, J = 6.6 Hz, 1H), 7.25-7.28 (d, J = 8.4 Hz, 2H), 7.35-7.41 (m, 2H) .
