反应详情

A solution of hydrochloric acid (12N, 12.5 mL) in dioxane (25 mL) is added to 4-methyl piperidine-1,4-dicarboxylic acid-1-tert-butyl ester-4-ethyl ester (7.5 g, 0.028 mol) and stirred at room temperature for 1 hr. The reaction mixture is concentrated under reduced pressure and the residue is treated with aqueous solution of sodium bicarbonate to adjust the pH to 8-9. It is again concentrated under reduced pressure and the residue is treated with dichloromethane. After drying over sodium sulfate solvent is removed to get the crude residue which is purified by column chromatography (silica gel 230-400 mesh, methanol:dichloromethane:ammonium hydroxide 14:85:1) to get 4-methylpiperidine-4-carboxylic acid ethyl ester.

1. concentrationThe reaction mixture is concentrated under reduced pressure
2. additionthe residue is treated with aqueous solution of sodium bicarbonate
3. concentrationIt is again concentrated under reduced pressure
4. additionthe residue is treated with dichloromethane
5. dry with materialAfter drying over sodium sulfate solvent
6. customis removed
7. customto get the crude residue which
8. customis purified by column chromatography (silica gel 230-400 mesh, methanol:dichloromethane:ammonium hydroxide 14:85:1)