反应详情

To a solution of dimethyl 2-(3-fluoro-4-(trifluoromethyl)benzyl)piperidine-1,4-dicarboxylate (7.17 g, 19.00 mmol) in acetonitrile (60 mL) and water (1.2 mL) was added lithium bromide (13.20 g, 152.02 mmol) and triethylamine (10.54 mL, 76.01 mmol). The resulting mixture was heated under reflux for 2 h, then cooled to room temperature. Water was added and acetonitrile removed by evaporation. The aqueous layer was further diluted with water, then washed with MTBE. The organic layer was extracted with water. The combined aqueous layers were acidified with 3.8 M HCl, a colorless precipitate formed. The solids were extracted with DCM 6 times. The aqueous layer was extracted twice again with DCM. The combined organic layers were dried over MgSO4 and evaporated. 2-(3-Fluoro-4-(trifluoromethyl)benzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (6.56 g, 95%) was isolated as an off-white solid. MS m/z 364 (M+H)+

1. temperatureThe resulting mixture was heated
2. temperatureunder reflux for 2 h
3. customacetonitrile removed by evaporation
4. additionThe aqueous layer was further diluted with water
5. washwashed with MTBE
6. extractionThe organic layer was extracted with water
7. customa colorless precipitate formed
8. extractionThe solids were extracted with DCM 6 times
9. extractionThe aqueous layer was extracted twice again with DCM
10. dry with materialThe combined organic layers were dried over MgSO4
11. customevaporated