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 dropwise added to a solution of oxalyl chloride (15.0 ml, 171 mmol) in CH2Cl2 (300 ml) in 30 min while maintaining the internal temperature below −65° C. A solution of 3 (46.7 g, 142 mmol) in CH2Cl2 (300 ml) was added dropwise in 15 min. while maintaining the temperature below −65° C. The reaction mixture was stirred an additional 45 minutes at −78° C., after which Et3N (99.0 ml, 712 mmol) was added. After the reaction mixture was stirred at −78° C. for 45 min, the reaction mixture was allowed to warm to room temperature and stirring was continued for an additional hour. The reaction mixture was washed with H2O and brine, dried (Na2SO4) and concentrated. The residue was dissolved in Et2O, filtered and the filtrate was concentrated and crystallized (Et2O/heptane) to result in 4 (30.9 g, 67%). The mother liquor was concentrated and crystallized (Et2O/heptane) and gave extra 4 (2.27 g, 5%).

1. temperaturewhile maintaining the internal temperature below −65° C
2. temperaturewhile maintaining the temperature below −65° C
3. stirringAfter the reaction mixture was stirred at −78° C. for 45 min
4. temperatureto warm to room temperature
5. stirringstirring
6. waitwas continued for an additional hour
7. washThe reaction mixture was washed with H2O and brine
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated
10. dissolutionThe residue was dissolved in Et2O
11. filtrationfiltered
12. concentrationthe filtrate was concentrated
13. customcrystallized (Et2O/heptane)

ORD record

ord-3221b3f1f5fe40e893bcc6eea6794c83

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08124624B2