3,3-Dichloro-5,5-dimethylpiperidin-2-one → 3-Chloro-5,5-dimethylpiperidin-2-one

To 40.8 g (0.21 mol) of 3,3-dichloro-5,5-dimethyl-2-piperidone dissolved in 410 mL of AcOH was added 10% Pd/C (50% wet, 6.2 g) and NaOAc-3H2O (62.4 g, 0.46 mol) and the mixture was hydrogenated at 300 kPa for 20 min. The pressure of hydrogen was adjusted at 300 kPa every 5 min. The catalyst was removed by filtration and the filtrate concentrated under reduced pressure. CHCl3 (400 mL) and water (300 mL) were added to the residue and the aqueous layer was neutralized with 4 mol/L NaOH. The mixture was separated and the aqueous layer was extracted with CHCl3 (5×300 mL) and the organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, and then the column was eluted with hexane-AcOEt (1:1). The titled compound was obtained as a white solid (20.4 g, 59.9%). (J. Med. Chem., 20, 1176 (1977))

1. customThe catalyst was removed by filtration
2. concentrationthe filtrate concentrated under reduced pressure
3. additionCHCl3 (400 mL) and water (300 mL) were added to the residue
4. customThe mixture was separated
5. extractionthe aqueous layer was extracted with CHCl3 (5×300 mL)
6. dry with materialthe organic layer was dried (MgSO4)
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure
9. washthe column was eluted with hexane-AcOEt (1:1)

ORD record

ord-eb16efe64d354615a526a9291b0c5f47

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07112582B2