反应详情

Dimethyl 2-(3,4-difluorobenzyl)piperidine-1,4-dicarboxylate (7.010 g, 21.42 mmol) was dissolved in acetonitrile (75 mL) and water (1.5 mL). Lithium bromide (14.88 g, 171.33 mmol) and triethylamine (11.87 mL, 85.66 mmol) were added and the resulting yellow suspension was heated at reflux for 3 h. Water (100 mL) and MTBE (300 mL) were added. The organic phase was extracted with water (×2). The pooled aqueous layer was acidified to pH 1 with 3.8 M HCl and then extracted with MTBE (×2). The combined organic layer was washed with water, dried over Na2SO4, filtered and evaporated to yield 2-(3,4-difluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (6.62 g, 99%) as a yellow solid. MS m/z 314 (M+H)+

1. temperaturethe resulting yellow suspension was heated
2. temperatureat reflux for 3 h
3. extractionThe organic phase was extracted with water (×2)
4. extractionextracted with MTBE (×2)
5. washThe combined organic layer was washed with water
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated