[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[Cl:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[NH2:18].[Br:19][C:20]1[C:21]([F:31])=[C:22]([F:30])[C:23](F)=[C:24]([CH:28]=1)[C:25]([OH:27])=[O:26]>C1COCC1>[Br:19][C:20]1[C:21]([F:31])=[C:22]([F:30])[C:23]([NH:18][C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][C:12]=2[Cl:11])=[C:24]([CH:28]=1)[C:25]([OH:27])=[O:26]To a solution of LiHMDS (49.0 mL, 2 M in THF/heptane) in THF (40 mL) was added 2-chlorophenylamine (6.50 mL, 60.6 mmol) at −78° C. After vigorous stirring for 10 minutes, a solution of 5-bromo-2,3,4-trifluoro-benzoic acid (2) (7.70 g, 30.2 mmol) in THF (60 mL) was added. The dry-ice bath was removed and the reaction mixture stirred for 4 hours at room temperature. The mixture was concentrated, treated with 10% aqueous HCl (75 mL), and extracted with EtOAc. The combined organic extracts were dried over MgSO4, filtered, and concentrated. Purification by trituration with boiling CH2Cl2 gave 7.24 g (66%) of the desired acid (3) as a yellow solid
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