反应详情

To a solution of 2,5-difluoro-4-methylbenzoic acid (5 g, 2.904 mmol) in ethanol (100 mL) was added concentrated sulfuric acid (1 mL). The reaction mixture was stirred at reflux for 18 hours. LCMS showed complete consumption of starting material, so the solvents were removed in vacuo and the resulting residue redissolved in EtOAc (50 mL), and washed with saturated aqueous sodium bicarbonate. The organic layer was separated, and the aqueous layer extracted with EtOAc (2×50 mL). The combined organics were dried over sodium sulfate and evaporated to yield the title compound as a pale yellow oil (5.502 g, 95%).

1. temperatureat reflux for 18 hours
2. customconsumption of starting material
3. customso the solvents were removed in vacuo
4. dissolutionthe resulting residue redissolved in EtOAc (50 mL)
5. washwashed with saturated aqueous sodium bicarbonate
6. customThe organic layer was separated
7. extractionthe aqueous layer extracted with EtOAc (2×50 mL)
8. dry with materialThe combined organics were dried over sodium sulfate
9. customevaporated