[NH:1]1[CH2:6][CH2:5][CH2:4][CH2:3][C@H:2]1[C:7]([OH:9])=[O:8].S(Cl)(Cl)=O.[CH3:14]O>>[CH3:14][O:8][C:7]([C@@H:2]1[CH2:3][CH2:4][CH2:5][CH2:6][NH:1]1)=[O:9]To a mixture of (S)-piperidine-2-carboxylic acid (10 mmol, 1.29 g) in MeOH (20 mL) is dropwise added thionyl chloride (30 mmol, 2.17 mL) at room temperature. The mixture is stirred at 2 hours, and then concentrated under reduced pressure. To the residue is added water (5 mL) and basified with potassium carbonate. The mixture is extracted with CH2Cl2. The combined organic layer is dried over Na2SO4, filtrated, and concentrated under reduced pressure to give (S)-piperidine-2-carboxylic acid methyl ester as a pale brown oil (800 mg, 56%).
Wird geladen…