[Br:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]([CH2:10][OH:11])=[CH:4][C:3]=1[O:12][CH3:13].O1CCC[CH2:15]1.C[Li].[Cl-].[NH4+]>ClC(Cl)C.C1(C)C=CC=CC=1.[O-2].[O-2].[Mn+4]>[Br:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]([CH:10]([OH:11])[CH3:15])=[CH:4][C:3]=1[O:12][CH3:13]
To a solution of (4-bromo-3,5-dimethoxyphenyl)methanol (14.5 g, 58.7 mmol) in dichloroethane (100 ml) and toluene (140 mL) was added manganese dioxide (25.5 g, 294 mmol) and the mixture was stirred at 80° C. for three hours. After the reaction was completed, the mixture was filtered with Celite and the solvent was distilled off under reduced pressure to obtain a crude compound. To a tetrahydrofuran (153 mL) solution of the crude compound (13.8 g, 56.3 mmol) was added dropwise 1.04M methyllithium (59.5 mL, 61.9 mmol) at −78° C., and the mixture was stirred for four hours. After the reaction was completed, a saturated aqueous solution of ammonium chloride was added to the reaction mixture, which was extracted with ethyl acetate, and dried over anhydrous magnesium sulfate, and the solvent was then distilled off under reduced pressure. The residue was purified by silica gel column chromatography (n-heptane/ethyl acetate: 4/1 then 1/1) to obtain the title compound (11.4 g, 43.7 mmol).
Loading…
