[Br:1][C:2]1[CH:3]=[C:4]([C:8]([C:10]2[CH:15]=[C:14]([O:16][CH3:17])[C:13]([O:18][CH3:19])=[CH:12][C:11]=2[NH:20]C(=O)C(C)(C)C)=[O:9])[CH:5]=[CH:6][CH:7]=1.Cl>O1CCOCC1>[NH2:20][C:11]1[CH:12]=[C:13]([O:18][CH3:19])[C:14]([O:16][CH3:17])=[CH:15][C:10]=1[C:8]([C:4]1[CH:5]=[CH:6][CH:7]=[C:2]([Br:1])[CH:3]=1)=[O:9]To a solution of N-{2-[(3-bromophenyl)carbonyl]-4,5-dimethoxyphenyl}-2,2-dimethylpropanamide (7.9 g, 18.9 mmol) in 1,4-dioxane (80 mL) was added concentrated HCl (9.55 g, 94.2 mmol). The mixture was refluxed for 2 hours. After cooling to room temperature, 1,4-dioxane was removed in vacuum and the residue was diluted with water (100 mL) and EtOAc (100 mL), then neutralized with NaHCO3 to pH=8. The mixture was extracted with EtOAc (80 mL×3). The combined organic phases were dried over anhydrous MgSO4, filtered and concentrated under vacuum to afford (2-amino-4,5-dimethoxyphenyl)(3-bromophenyl)methanone. MS (M+H)=336 and 338.
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