反应详情

5-Bromo-6-(2,2,2-trifluoro-ethoxy)-2-trifluoromethyl-nicotinic acid ethyl ester (244 g, 0.61 mol) was dissolved in a mixture of tetrahydrofuran (2100 mL) and water (700 mL). Lithiumhydroxid monohydrate (77 g, 1.85 mol) was added and the mixture was stirred and heated at reflux-temperature for 1.5 h. After cooling to room temperature the mixture was acidified with hydrochloric acid (2N, 750 mL). The mixture was extracted with diethylether (1×1500 mL, 1×1000 mL), and the organic phases were washed with brine (1000 mL). The organic phases were combined, dried with MgSO4 and the solvent was evaporated to give the title compound (224 g) as off-white solid; MS (ISP) 365.9, 367.9 (M−H).

1. temperatureheated
2. temperatureat reflux-temperature for 1.5 h
3. extractionThe mixture was extracted with diethylether (1×1500 mL, 1×1000 mL)
4. washthe organic phases were washed with brine (1000 mL)
5. dry with materialdried with MgSO4
6. customthe solvent was evaporated