反应详情

Dimethyl 2-(2,6-difluorobenzyl)piperidine-1,4-dicarboxylate (5.98 g, 18.27 mmol) was dissolved in acetonitrile (50 mL) and water (1 mL), then lithium bromide (12.69 g, 146.16 mmol) and triethylamine (10.13 mL, 73.08 mmol) were added. The suspension was heated to reflux for 3.5 h, then water (60 mL) and MTBE (180 mL) were added. The organic phase was extracted with water (×2). The combined water phases were acidified to pH 1 with 3.8 M HCl and extracted with MTBE (×2). The combined organic phases were washed with water, dried with MgSO4, filtered through celite and concentrated to give 2-(2,6-difluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (4.72 g, 82%) as a light yellow solid. MS m/z 314 (M+H)+

1. temperatureThe suspension was heated
2. temperatureto reflux for 3.5 h
3. extractionThe organic phase was extracted with water (×2)
4. extractionextracted with MTBE (×2)
5. washThe combined organic phases were washed with water
6. dry with materialdried with MgSO4
7. filtrationfiltered through celite and
8. concentrationconcentrated