61155-69-9

24297-59-4

Step 2: Preparation of 2-(1H-indol-1-yl)acetic acid Ethyl 2-(1H-indol-1-yl)acetate (2.03 g, 10 mmol) was dissolved in ethanol (40 mL), aqueous sodium hydroxide solution (1 N, 50 mL) was added, and the reaction was stirred at room temperature for 1.5 hours. Upon completion of the reaction, the reaction solution was adjusted to slightly acidic with dilute hydrochloric acid and the mixture was subsequently concentrated under reduced pressure. The residue was extracted with ethyl acetate and the organic phase was washed with brine and the solvent was removed under reduced pressure to give pure 2-(1H-indol-1-yl)acetic acid (1.6 g, 87% yield), (LC/MS: m/z = 176.3 [M+H]+).