[Br:1][C:2]1[CH:3]=[C:4]([NH:8][C:9]2[CH:17]=[C:16]([Cl:18])[CH:15]=[CH:14][C:10]=2[C:11]([OH:13])=O)[CH:5]=[CH:6][CH:7]=1.O.[H-].[Na+].[CH3:22]OS(OC)(=O)=O>OS(O)(=O)=O.CN(C=O)C>[Br:1][C:2]1[C:3]2[C:11](=[O:13])[C:10]3[C:9](=[CH:17][C:16]([Cl:18])=[CH:15][CH:14]=3)[N:8]([CH3:22])[C:4]=2[CH:5]=[CH:6][CH:7]=1
(Method E-3) 2-(3-Bromo-phenylamino)-4-chlorobenzoic acid, 14 (4 g, 12.2 mmol) was heated in conc. H2SO4 (50 ml) for 30 min then allowed to cool to room temperature. Water was added slowly and the precipitate filtered off, washed with water and dried over phosphorous pentoxide. The crude material was suspended in DMF (50 mL) and added under nitrogen to NaH (1.2 g, 50 mmol) in DMF (50 mL). After 30 min dimethylsulphate (3 ml, 18 mmol) was added and stirring continued for 1 hr. Addition of water gave a precipitate the title compound (625 mg, 2.02 mmol, 17%) as the more polar product after separation by column chromatography (ethyl acetate:hexane 1:4)
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