Dimethyl Sulfoxide → Methyl 4-(piperidin-2-yl)butanoate hydrochloride

Temperature

-78 °C

A solution of DMSO (21.24 ml, 299 mmol) in CH2Cl2 (600 ml) was added dropwise to a solution of oxalyl chloride (15.0 ml, 171 mmol) in CH2Cl2 (300 ml) at an internal temperature below −65° C. in the course of 30 min. A solution of 3 (46.7 g, 142 mmol) in CH2Cl2 (300 ml) was added dropwise in the course of 15 min, the temperature remaining below −65° C. The reaction mixture was stirred at −78° C. for a further 45 min and Et3N (99.0 ml, 712 mmol) was then added. After the reaction mixture had been stirred at −78° C. for 45 min, the reaction mixture was warmed to room temperature, while stirring, and was then stirred for a further hour. The reaction mixture was washed with H2O and sat. NaCl solution, dried over Na2SO4 and concentrated. The residue was dissolved in ether, the solution was filtered, the filtrate was concentrated and the residue was recrystallized (Et2O/heptane) to obtain 4 (30.9 g, 67%). The mother liquor was concentrated and the residue was recrystallized (Et2O/heptane) and gave additional product 4 (2.27 g, 5%).

1. customremaining below −65° C
2. stirringAfter the reaction mixture had been stirred at −78° C. for 45 min
3. temperaturethe reaction mixture was warmed to room temperature
4. stirringwhile stirring
5. stirringwas then stirred for a further hour
6. washThe reaction mixture was washed with H2O and sat. NaCl solution
7. dry with materialdried over Na2SO4
8. concentrationconcentrated
9. dissolutionThe residue was dissolved in ether
10. filtrationthe solution was filtered
11. concentrationthe filtrate was concentrated
12. customthe residue was recrystallized (Et2O/heptane)

ORD record

ord-a9a2b81c4edf4a6797e11d153a0918f4

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08318769B2