[CH3:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[CH3:11])[C:5]([OH:7])=[O:6].S(=O)(=O)(O)O.[CH3:17]O>>[CH3:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[CH3:11])[C:5]([O:7][CH3:17])=[O:6]3,4-Dimethylbenzoic acid (64.4 g, 429 mmol) was dissolved in methanol (600 ml), and sulfuric acid (9 ml) was added, which was followed by reflux under heating for 5 hours. The reaction mixture was concentrated to 160 ml and water was added. The mixture was extracted with ethyl acetate, and the organic extract was washed successively with water, 10% aqueous sodium hydroxide solution and saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated to give 68.0 g of methyl 3,4-dimethylbenzoate (yield 97%).
Wird geladen…