[NH2:1]/[C:2](/[CH3:11])=[CH:3]\[C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5].[F:12][C:13]([F:23])([F:22])[C:14]1[C:15](=[O:21])[CH:16]=[CH:17][C:18](=O)[CH:19]=1.C(Cl)Cl>CCO>[OH:21][C:15]1[C:14]([C:13]([F:12])([F:22])[F:23])=[C:19]2[C:18](=[CH:17][CH:16]=1)[NH:1][C:2]([CH3:11])=[C:3]2[C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5]A stirred solution of 1,1-dimethylethyl (2Z)-3-amino-2-butenoate (47.6 g, 0.3 mol) in EtOH (100 mL) was treated dropwise at ambient temperature with a 1.2 M solution of 2-(trifluoromethyl)-2,5-cyclohexadiene-1,4-dione in CH2Cl2 (300 mL, 0.35 mol) (internal temperature rose to +35° C. during the addition). The reaction was stirred 1 h and concentrated at reduced pressure. Stirring the resulting material with CHCl3 at ice-bath temperature afforded 1,1-dimethylethyl 5-hydroxy-2-methyl-4-(trifluoromethyl)-1H-indole-3-carboxylate as an off-white solid which was collected by filtration (62 g, 66% yield): 1H NMR (DMSO-d6) δ 11.55 (s, 1H), 9.68 (bs, 1H), 7.33 (d, J=8.8 Hz, 1H), 6.76 (d, J=8.8 Hz, 1H), 2.37 (s, 3H), 1.45 (s, 9H).
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