[Br:1][C:2]1[CH:10]=[CH:9][C:5]([C:6](O)=[O:7])=[CH:4][C:3]=1[F:11].S(Cl)(Cl)=O.[Cl-].[NH4+].C([NH:21]C(C)C)(C)C>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([NH2:21])=[O:7])=[CH:4][C:3]=1[F:11]
To a suspension of 4-bromo-3-fluorobenzoic acid (1.50 g, 6.85 mmol) in toluene (10 mL) at ambient temperature was added thionyl chloride (1.0 mL, 14 mmol). The reaction mixture was heated at 70° C. for 17 hours, at reflux for 1.5 hours, stirred at ambient temperature for 75 hours, heated at reflux for 18.5 hours, and stirred at ambient temperature for 1 hour. Thionyl chloride (0.25 mL, 3.4 mmol) was added and the reaction mixture was heated at reflux for 3 hours. The reaction was cooled and condensed to an oily solid mixture. Toluene (10 mL), ammonium chloride (0.73 g, 14 mmol) and diisopropylamine (3.6 mL, 21 mmol) were added, and the mixture was stirred at ambient temperature for 17 hours, heated at 50° C. for 5 hours, then cooled to ambient temperature. The reaction mixture was partitioned between EtOAc (10 mL) and H2O (10 mL), separated, and the aqueous layer further extracted with EtOAc (15 mL). The combined organic extracts were washed with 1N HCl (20 mL), 1N NaOH (20 mL), brine (20 mL), dried (MgSO4), filtered, and concentrated to afford 4-bromo-3-fluorobenzamide (0.938 g, 63%) as a light-yellow solid which was carried on without further purification.
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