General procedure for the synthesis of 2-(1-benzyl-5-(4-(trifluoromethoxy)phenyl)-1H-indol-3-yl)-2-oxoacetic acid from compound (CAS: 481630-47-1): ethyl 2-{1-benzyl-5-[4-(trifluoromethoxy)phenyl]-1H-indol-3-yl}-2-oxoacetate (0.463 g, 0.991 mmol) was stirred with potassium hydroxide (0.224 g, 3.99 mmol) in a mixture of tetrahydrofuran (5 mL) and water (5 mL) at 50 °C for 40 min. After completion of the reaction, the mixture was cooled to room temperature, poured into excess water, acidified with 2N hydrochloric acid and extracted with ethyl acetate. The organic phase was washed sequentially with water and brine, dried over anhydrous magnesium sulfate and subsequently concentrated to dryness under reduced pressure. The residue was dried at 80 °C for 15 h to give 2-(1-benzyl-5-(4-(trifluoromethoxy)phenyl)-1H-indol-3-yl)-2-oxoacetic acid as a light yellow solid (0.314 g, 78%) with melting point 169-171 °C. For analysis, the sample was recrystallized from acetonitrile. Mass spectrum (+APCI, [M+H]+) m/z 440; 1H NMR (400 MHz, DMSO-d6): δ 13.8-14.2 (br, 1H), 8.75 (s, 1H), 8.45 (d, 1H, J=1.5 Hz), 7.75-7.8 (m, 2H), 7.7 (d, 1H, J=8.5 Hz), 7.6 ( dd, 1H, J=8.7 Hz), 7.45 (d, 2H, J=8.8 Hz), 7.25-7.35 (m, 5H), 5.65 ppm (s, 2H). Elemental analysis C24H16F3NO4: calculated values: C, 65.61; H, 3.67; N, 3.19. measured values: C, 65.59; H, 3.54; N, 3.17.