反应详情

Dimethyl 2-(4-fluorobenzyl)piperidine-1,4-dicarboxylate (5.797 g, 18.74 mmol) was dissolved in acetonitrile (60 mL) and water (1.2 mL), then lithium bromide (13.02 g, 149.92 mmol) was added. Triethylamine (10.39 mL, 74.96 mmol) was added and the resulting yellow suspension was heated at reflux for 1.5 h. water (60 mL) and MTBE (120 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 and evaporated. Traces of water were azeotropically removed by MeCN. 2-(4-Fluorobenzyl)-1-(methoxycarbonyl)piperidine-4-carboxylic acid (4.43 g, 80%) was isolated as a beige solid. MS m/z 296 (M+H)+

1. temperaturethe resulting yellow suspension was heated
2. additionwere added
3. extractionThe organic phase was extracted with water (×2)
4. extractionextracted with MTBE (×2)
5. washThe combined organic layer was washed with water
6. customevaporated
7. customTraces of water were azeotropically removed by MeCN