反应详情

Dimethyl 2-(4-(methylsulfonyl)benzyl)piperidine-1,4-dicarboxylate (5.5 g, 14.89 mmol) was dissolved in acetonitrile (50 mL) and water (1 mL), then lithium bromide (10.34 g, 119.10 mmol) and triethylamine (8.25 mL, 59.55 mmol) were added and the resulting suspension was heated at reflux for 2 h. Water and MTBE were added. The organic phase was extracted with water (×2). To the pooled aqueous layer was added ethyl acetate and the solution was acidified to pH 1 with HCl and then extracted with ethyl acetate twice. The organic layer was dried (Na2SO4), filtered through celite and evaporated to yield 1-(methoxycarbonyl)-2-(4-(methylsulfonyl)benzyl)piperidine-4-carboxylic acid (4.2 g, 79%). MS m/z 354 (M−H)−

1. temperaturethe resulting suspension was heated
2. temperatureat reflux for 2 h
3. extractionThe organic phase was extracted with water (×2)
4. additionTo the pooled aqueous layer was added ethyl acetate
5. extractionextracted with ethyl acetate twice
6. dry with materialThe organic layer was dried (Na2SO4)
7. filtrationfiltered through celite
8. customevaporated