The reaction was slowly added dropwise to 8.8 mL of 2M LDA (a mixture of heptane, THF, and ethylbenzene) containing 1 g of 2-chlorophenylacetic acid, followed by the addition of 1.58 g of HMPA and 5 mL of THF under ice-bath cooling conditions, and stirred for 1 hour at room temperature. After completion of the reaction, 1.25 g of iodomethane was added under cooling in an ice bath and stirring was continued for 30 min at room temperature. The reaction mixture was poured into ice water and acidified with 10% aqueous hydrochloric acid, followed by extraction with ethyl acetate. The organic phases were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. The resulting crude product was purified by chromatography on a 30 g silica gel column (eluent ratio chloroform:methanol=20:1) to give 0.928 g of the target compound 2-(2-chlorophenyl)propionic acid in 86% yield as a light yellow oil.1H-NMR (CDCl3) δ: 7.50-7.10 (m, 4H), 4.27 (q, J=7.2 Hz, 1H). 1.52 (d, J=7.2Hz, 3H). Mass spectral data: m/e 184 (M+), 139 (base peak).
