69999-15-1

71922-83-3

69999-15-1

2-Amino-2-(2,3-dihydrobenzofuran-5-yl)acetic acid (200 mg, 1.04 mmol) was used as starting material and dissolved in glacial acetic acid (250 mg, 4.14 mmol). An aqueous solution of sodium nitrite (145 mg, 2.08 mmol) was added dropwise (~5 mL) under stirring. Subsequently, additional glacial acetic acid (1 mL) was added and the reaction mixture was heated to 65 °C and kept at this temperature for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature, diluted with water and extracted several times with ethyl acetate. The organic phases were combined, dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to afford the target product 2-(2,3-dihydrobenzofuran-5-yl)-2-hydroxyacetic acid in about 65% yield. The product was confirmed by NMR hydrogen spectrum (DMSO-D6): δ 7.15 (m, 3H), 5.18 (d, 1H), 4.78 (t, 2H), 3.34 (t, 2H).