Methyl iodide → (S)-2-Methoxy-3-phenylpropanoic acid

(S)-2-Hydroxy-3-phenylpropanoic acid (1.0 g, 6.02 mmol) was dissolved in THF (100 ml), sodium hydride (0.48 g, 12.00 mmol) and methyl iodide (1.71 g, 12.04 mmol) were added, and the mixture was stirred at 65° C. for one hour. After leaving to cool, the reaction solution was concentrated under reduced pressure and adjusted to pH 4 by adding a 6 M aqueous hydrochloric acid solution thereto. The aqueous layer was extracted with ethyl acetate, the organic layer was concentrated, and the resulting residue was purified by column chromatography (dichloromethane:methanol=10:1) to afford the title compound (0.71 g, 59%).