[Br:1][C:2]1[CH:3]=[CH:4][C:5]([NH:12][C:13](=[O:23])[CH2:14][O:15][C:16]2[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=2)=[C:6]([CH:11]=1)[C:7](OC)=[O:8].C[Si]([N-][Si](C)(C)C)(C)C.[K+].C(=O)=O.CC(C)=O>C1COCC1>[Br:1][C:2]1[CH:11]=[C:6]2[C:5](=[CH:4][CH:3]=1)[NH:12][C:13](=[O:23])[C:14]([O:15][C:16]1[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=1)=[C:7]2[OH:8]To a suspension of methyl 5-bromo-2-(2-(4-chlorophenoxy)acetamido)benzoate (5.15 g, 12.9 mmol, Intermediate 7: step a) in THF (140 mL) at −78° C. was added potassium bis(trimethylsilyl)amide (0.5 M in toluene, 76.7 mL, 38.4 mmol) over 4 minutes, and the mixture was stirred for 5 minutes. The dry-ice/acetone bath was replaced an with an ice-water bath and the reaction was stirred for 1.5 hours. The reaction was then quenched with water and ethyl acetate was added. The organic layer was removed and the aqueous layer was acidified with 2 N HCl (kept pH above 2). An off-white precipitate formed which was filtered and the solid was dried overnight in the air to yield the title compound.
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