[CH3:1][O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][C:6]([OH:11])=[C:5]([N+:12]([O-:14])=[O:13])[CH:4]=1.[C:15](=O)([O-])[O-].[K+].[K+].IC>CN(C=O)C>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([N+:12]([O-:14])=[O:13])[C:6]([O:11][CH3:15])=[CH:7][C:8]=1[O:9][CH3:10]A mixture of 4,5-dimethoxy-2-nitro-phenol (2.00 g, 10 mmol), potassium carbonate (2.76 g, 20 mmol) and iodomethane (0.75 mL, 12 mmol) in DMF was placed in a sealed tube and heated at 75-80° C. for 20 h. The reaction was cooled and was filtered through Celite, washing with ethyl acetate. The filtrate was washed with water (the first wash was back-extracted with ethyl acetate), sodium bicarbonate and brine, was dried (sodium sulfate) and was evaporated. Purification by flash chromatography (SiO2) eluted with 1:1 ethyl acetate:hexanes provided 1,2,4-trimethoxy-5-nitro-benzene (1.20 g, 57% yield) as a yellow solid. 1H-NMR (CDCl3, 500 MHz) 7.53 (s, 1H), 6.50 (s, 1H), 3.92 (s, 3H), 3.91 (s, 3H), 3.84 (s, 3H) ppm; MS (FIA) 214.1 (M+H); HPLC (Method A) 3.253 min.
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