反应详情

Dimethyl 2-(2-fluorobenzyl)piperidine-1,4-dicarboxylate (6.16 g, crude) was dissolved in acetonitrile (45 mL) and water (0.9 mL). Lithium bromide (13.84 g, 159.39 mmol) and triethylamine (11.05 mL, 79.69 mmol) were added and the mixture was heated at reflux overnight. Water (90 mL) and MTBE were added. The organic phase was extracted with water (×2). To the pooled aqueous layer was added MTBE and the solution was acidified to pH 1 with 2 M HCl and then extracted with MTBE (×2). The combined organic layer was dried over Na2SO4 and evaporated to give 2-(2-fluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (4.48 g, 76%) as a slightly yellow semisolid. MS m/z 296 (M+H)+

1. temperaturethe mixture was heated
2. temperatureat reflux overnight
3. extractionThe organic phase was extracted with water (×2)
4. additionTo the pooled aqueous layer was added MTBE
5. extractionextracted with MTBE (×2)
6. dry with materialThe combined organic layer was dried over Na2SO4
7. customevaporated