反应详情

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).

1. customto give an aqueous layer of pH 4
2. extractionextract the mixture into a solution of 10% DCM in diethyl ether (300 mL)
3. customto remove some dark solid matter
4. concentrationBasify the aqueous phase to pH 8 with 2M aqueous sodium hydroxide solution, then saturate with solid sodium chloride
5. extractionExtract into a 10% solution of isopropanol in chloroform
6. additionAdd further 2M aqueous sodium hydroxide
7. temperatureto maintain pH 8
8. extractionRepeat the extraction into a 10% solution of isopropanol in chloroform
9. customhas been recovered
10. washWash the isopropanol in chloroform solution with brine
11. dry with materialdry over Na2SO4
12. filtrationfilter
13. customevaporate