[NH2:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[Br:12]N1C(=O)CCC1=O>CN(C)C=O>[NH2:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([Br:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]To a solution of 2-amino-4-fluorobenzoic acid (10 g, 64.5 mmol) in N,N-dimethylformamide (100 mL) at −10° C., was added dropwise a solution of N-bromosuccinimide (11.2 g, 62.9 mmol) in N,N-dimethylformamide (50 mL) over 1 hour. After the addition was complete, the mixture was stirred at −10° C. for 1 hour. The reaction was quenched with aqueous sodium bisulfate and partitioned between ethyl acetate and water. The organic layer was separated, and the aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with water and then with brine, and then dried over sodium sulfate. The sample was concentrated to give the crude product 27 (14.5 g, yield: 96.5%), which was used for the next step without further purification.
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