反应详情

The crude 5-bromo-2-methylbenzoic acid (1) (60.8 g; 283 mmol) was stirred in methanol (400 mL) and concentrated sulfuric acid (6 mL) was added. The mixture was heated at gentle boiling for 20 hours. The solvent was evaporated and the residue was taken up into toluene and water. The solution was shaken and the phases were separated. The organic layer was washed with dilute aqueous NaHCO3, water, and brine. The solution was dried with MgSO4, filtered, and evaporated to get an orange oil. Fractional distillation at reduced pressure yields a mixture of the title compound and 3-bromo-2-methylbenzoic acid methyl ester (47.9 g; 74%).

1. temperatureThe mixture was heated at gentle boiling for 20 hours
2. customThe solvent was evaporated
3. customthe phases were separated
4. washThe organic layer was washed with dilute aqueous NaHCO3, water, and brine
5. dry with materialThe solution was dried with MgSO4
6. filtrationfiltered
7. customevaporated
8. customto get an orange oil
9. distillationFractional distillation at reduced pressure
10. customyields