F[S:2]([C:5]1[CH:11]=[C:10]([Br:12])[CH:9]=[C:8]([Br:13])[C:6]=1[NH2:7])(=[O:4])=[O:3].[CH3:14][Li]>CCOCC>[Br:13][C:8]1[CH:9]=[C:10]([Br:12])[CH:11]=[C:5]([S:2]([CH3:14])(=[O:4])=[O:3])[C:6]=1[NH2:7]A solution of 2-fluorosulfonyl-4,6-dibromoaniline (7.19 g; 0.0216 mol) in ether (100 ml) is cooled to -65° C. under a nitrogen atmosphere and a solution of methyllithium in ether (37.5 ml of 1.8 M; 0.0675 mol) is added via a syringe. The mixture is allowed to warm to 0° C., the solution is poured into ice, and the ether layer is separated. The aqueous layer is extracted with ether (3×100 ml) and the ether layers are combined. The solvent is removed under reduced pressure and the residue crystallized from petroleum ether to afford the title product.
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