[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9]([CH:11]=[CH:12][C:13]([O:15]C)=[O:14])[CH:10]=1)[NH:7][CH:6]=[C:5]2[CH3:17].[OH-].[Na+]>C1COCC1.CO>[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9](/[CH:11]=[CH:12]/[C:13]([OH:15])=[O:14])[CH:10]=1)[NH:7][CH:6]=[C:5]2[CH3:17]To a stirred solution of methyl 3-(5-fluoro-3-methylindol-7-yl)acrylate (1.75 kg, 7.51 mole), prepared as described in Example 1, in 23.4 L THF/MeOH (1:1) at room temperature was added 2 M aqueous sodium hydroxide (16.35 L, 32.7 moles). Stirring was continued for 15 h, then the reaction mixture was concentrated in vacuo to remove the volatile organic solvents. The solution was diluted with 20 L water, then extracted with dichloromethane (3×10 L). The aqueous layer was acidified to a pH of 2-3 with 2 M HCl, which induced precipitation of the product. The product was collected via vacuum filtration, washed with water (2×2 L), and vacuum dried at 60° C. to afford 1.036 kg (91% yield) of the desired title compound: 1H NMR (400 MHz, DMSO-d6) δ 2.23 (d, 3H, J=0.8 Hz), 6.67 (d, 1H, J=16 Hz), 7.24 (br s, 1H), 7.34 (dd, 1H, J=9.2, 2.4 Hz), 7.41 (dd, 1H, J=10.4, 2.4 Hz), 8.06 (dd, 1H, J=16, 1.2 Hz), 11.35 (s, 1H).
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