反应详情

To a solution of 2,3,4-trimethoxybenzoic acid (25 g) in dry methanol (250 ml), concentrated sulfuric acid (2.4 ml) was added. The reaction solution was refluxed for 20 hr, concentrated to half its volume by evaporation, and poured into a mixture of ice and water. The solution was extracted with methylene chloride and the organic extract was washed with cold aqueous sodium carbonate solution and water, dried over sodium sulfate and evaporated to give 25.4 g of 2,3,4-trimethoxybenzoic acid, methyl ester: ir (CHCl3) 1720 cm-1 ; and nmr (CDCl3) δ 3.85 (s, 3H), 3.87 (s, 3H), 3.92 (s, 6H), 6.65 (d, 1H) and 7.55 (d, 1H).

1. temperatureThe reaction solution was refluxed for 20 hr
2. concentrationconcentrated to half its volume by evaporation
3. additionpoured into a mixture of ice and water
4. extractionThe solution was extracted with methylene chloride
5. extractionthe organic extract
6. washwas washed with cold aqueous sodium carbonate solution and water
7. dry with materialdried over sodium sulfate
8. customevaporated