[ClH:1].Cl.[CH3:3][C:4]([CH3:16])([CH2:9][N:10]1[CH2:15][CH2:14][NH:13][CH2:12][CH2:11]1)[C:5]([O:7][CH3:8])=[O:6].C(=O)(O)[O-].[Na+]>O>[ClH:1].[CH3:3][C:4]([CH3:16])([CH2:9][N:10]1[CH2:15][CH2:14][NH:13][CH2:12][CH2:11]1)[C:5]([O:7][CH3:8])=[O:6]Dissolve methyl 2,2-dimethyl-3-(piperazin-1-yl)propanoate dihydrochloride (112.0 g, 409.95 mmoles) in water (250 mL). Add solid sodium bicarbonate to give an aqueous layer of pH 4 and extract the mixture into a solution of 10% DCM in diethyl ether (300 mL) to remove some dark solid matter and some color. Discard the organic layer. Basify the aqueous phase to pH 8 with 2M aqueous sodium hydroxide solution, then saturate with solid sodium chloride. Extract into a 10% solution of isopropanol in chloroform. Add further 2M aqueous sodium hydroxide to maintain pH 8. Repeat the extraction into a 10% solution of isopropanol in chloroform. Continue the extraction process until 85% of the expected material has been recovered. Wash the isopropanol in chloroform solution with brine, dry over Na2SO4, filter and evaporate to give methyl 2,2-dimethyl-3-(piperazin-1-yl)propanoate hydrochloride (82.1 g % yield). MS (m/z): 201.1 (M+1).
読み込み中…