Ethanol → 2-amino-5-bromo-N-methoxy-N-methylbenzamide

反応式

C([N:3]([CH2:6]C)CC)C.[Br:8][C:9]1[CH:20]=[C:13]2[C:14]([O:16]C(=O)[NH:18][C:12]2=[CH:11][CH:10]=1)=O.[CH2:21]([OH:23])C>O>[NH2:18][C:12]1[CH:11]=[CH:10][C:9]([Br:8])=[CH:20][C:13]=1[C:14]([N:3]([O:23][CH3:21])[CH3:6])=[O:16]

参加物

実験手順

To a mixture of N, O-dimethylhydroxylamine hydrochloride (9.42 g, 96 mmol) and triethyl amine (13.5 mL, 96 mmol) in ethanol and water (100 mL/10 mL) was added a solution of 5-bromoisatoic anhydride (20 g, 74 mmol) in ethanol and water (100 mL/10 mL) at ambient temperature under nitrogen. The reaction mixture was heated at reflux for 3 hours. The solvent was removed in vacuo and the residue was dissolved in ethyl acetate (100 mL), washed with 1N aqueous sodium hydroxide solution (2×20 mL), brine (30 mL), and dried with MgSO4. After removal of the solvent, the residue was purified by a silica gel flash chromatography (hexane:ethyl acetate/3:2) to give 2-amino-5-bromo-N-methoxy-N-methylbenzamide as an off-white solid (13 g, 68%): mp 80-81° C.; 1H-NMR (CDCl3) δ7.49 (d, 1H, J=2.1 Hz), 7.26 (dd, 1H, J=8.3, 2.0 Hz), 6.59 (d, 1H, J=8.4 Hz), 4.69 (br, 2H), 3.58 (s, 3H), 3.34 (s, 3H); Anal. Calc. For C9H11BrN2O2: C, 41.72, H, 4.28, N, 10.81. Found: C, 41.99, H, 4.16, N, 10.82.