Water → 3-Propylpiperidin-2-one

A solution of 4.2 g (42.3 mmol) of δ-valerolactam (5) in 35 mL of tetrahydrofuran was cooled to -78° C. under argon atmosphere. To this cooled solution, 32 mL of n-BuLi (2.5 M solution in hexane, 80 mmol) was added dropwise over a period of 40 minutes. The reaction mixture was warmed to room temperature and was magnetically stirred for 2 hours. The reaction mixture was cooled to 0° C. and a solution of 3.87 mL (42.5 mmol) of 1-bromopropane in 20 mL of tetrahydrofuran was added dropwise. The reaction mixture was warmed up to room temperature and stirred magnetically for 16 hours. The reaction mixture was treated with 75 mL of water and concentrated to remove tetrahydrofuran. The residue was extracted with 3×200 mL of diethyl ether. The organic layers were combined, washed with brine, dried over MgSO4 and concentrated to yield a white solid which was recrystallized from petroleum ether to yield 3.2 g (22.6 mmol, 54%) of tetrahydro-3-propylpyridin-2(1H)-one (6). NMR, IR and MS data confirmed the compound identity.

1. temperatureThe reaction mixture was cooled to 0° C.
2. temperatureThe reaction mixture was warmed up to room temperature
3. stirringstirred magnetically for 16 hours
4. concentrationconcentrated
5. customto remove tetrahydrofuran
6. extractionThe residue was extracted with 3×200 mL of diethyl ether
7. washwashed with brine
8. dry with materialdried over MgSO4
9. concentrationconcentrated
10. customto yield a white solid which
11. customwas recrystallized from petroleum ether

ORD record

ord-a79b21e5fa7741208badd7e9c613caea

Source dataset

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05986094