反应详情

A solution of 3,5-dimethyl benzoic acid (25 g, 0.17 mol) in methanol (250 ml) was treated with sulfuric acid (1 ml, cat. amount) and heated to reflux. After 10 hours, the solution was cooled to room temperature, concentrated to approximately 1/2 volume and poured into 200 ml of crushed ice. The mixture was extracted twice with 200 ml portions of diethyl ether. The organic phase was extracted with saturated aqueous sodium carbonate, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting solid was recrystallized from hexanes to yield the product (24.5 g, 90% yield) as volatile white plates. mp=32°-35° C. (lit. mp=35°-36° C.)

1. temperatureheated to reflux
2. concentrationconcentrated to approximately 1/2 volume
3. additionpoured into 200 ml of crushed ice
4. extractionThe mixture was extracted twice with 200 ml portions of diethyl ether
5. extractionThe organic phase was extracted with saturated aqueous sodium carbonate
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe resulting solid was recrystallized from hexanes