Cl.[CH3:2][NH:3][O:4][CH3:5].CCN(CC)CC.[Br:13][C:14]1[CH:15]=[C:16]([CH:20]=[C:21]([C:23]([O:25][CH3:26])=[O:24])[CH:22]=1)[C:17]([OH:19])=O.CCN=C=NCCCN(C)C.Cl.C1C=CC2N(O)N=NC=2C=1>C(Cl)Cl>[Br:13][C:14]1[CH:22]=[C:21]([CH:20]=[C:16]([C:17](=[O:19])[N:3]([O:4][CH3:5])[CH3:2])[CH:15]=1)[C:23]([O:25][CH3:26])=[O:24]N,O-Dimethylhydroxylamine hydrochloride (1.15 g, 11.8 mmol) was dissolved in CH2Cl2 (50 mL) and Et3N (4.8 mL, 34.4 mmol) was added. The solution was stirred for 30 min. The resultant solution was cooled to 0° C. and compound 3-bromo-5-(methoxycarbonyl)benzoic acid (2.55 g, 9.84 mmol) was added followed by EDC.HCl (3.77 g, 19.6 mmol) and HOBt (0.26 g, 1.96 mmol). The reaction mixture was allowed to come to room temperature and stirred for another 4 h. After completion, the reaction mixture was diluted with CH2Cl2. The organic layer was washed with water and brine solution and dried over anhydrous sodium sulfate. Solvent was removed under reduced pressure and the crude product was purified by column chromatography (silica 60-120 mesh, eluent 20% EtOAc in petroleum ether) to get methyl 3-bromo-5-(methoxy(methyl)carbamoyl)benzoate (2.3 g, yield 77%) as colorless liquid. 1H NMR (400 MHz, CDCl3) δ 8.29 (m, 1H), 8.27 (t, J=1.8 Hz, 1H), 8.02 (t, J=1.6 Hz, 1H), 3.95 (s, 3H), 3.57 (s, 3H), 3.39 (s, 3H). MS (ESI) m/z: Calculated for C11H12BrNO4: 300.99. found: 302.0 (M+H)+.
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