Aluminium lithium hydride → 1-(Methylsulfonyl)-2-piperidinemethanol

Ethyl 1-(methylsulfonyl)piperidine-2-carboxylate (6.9 g, 29.3 mmol) in anhydrous tetrahydrofuran (40 mL) was added slowly to a stirring suspension of lithium aluminum hydride (1.5 g, 40 mmol) in anhydrous tetrahydrofuran (80 mL) kept at 0° C. with an external ice bath. After fifteen minutes, the ice bath was removed and the reaction was allowed to warm to ambient temperature and stirred for an additional 4.5 hours. The mixture was cooled to 0° C., and water (1.5 mL) was added dropwise, followed by aqueous sodium hydroxide (1.5 mL), and water (4.5 mL). The mixture was stirred for 15 mins at room temperature, followed by the addition of magnesium sulfate and additional stirring. The mixture was filtered through Celite, washed three times with ether, and the combined organic fractions concentrated under reduced pressure. The crude residue was passed through a pad of silica gel, washing with ethyl acetate, to give the desired product as a clear liquid (4.9 g, 87%). 1H NMR (CDCl3, 300 MHz) δ 4.06-4.03 (m, 1H), 3.96-3.92 (dd, 1H, J=11.1, 9.3 Hz), 3.73-3.68 (br d, 1H, J=14.1 Hz), 3.61-3.56 (dd, 1H, J=11.1, 4.8 Hz), 3.12-3.03 (br t, 1H, J=12.1 Hz), 2.96 (s, 3H), 2.17 (br s, 1H), 1.74-1.47 (m, 6H).

1. customkept at 0° C. with an external ice bath
2. waitAfter fifteen minutes
3. customthe ice bath was removed
4. temperatureThe mixture was cooled to 0° C.
5. additionwater (1.5 mL) was added dropwise
6. stirringThe mixture was stirred for 15 mins at room temperature
7. additionfollowed by the addition of magnesium sulfate and additional stirring
8. filtrationThe mixture was filtered through Celite
9. washwashed three times with ether
10. concentrationthe combined organic fractions concentrated under reduced pressure
11. washwashing with ethyl acetate

ORD record

ord-70cb2f0964784614a5a4c9af540a7e19

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09265772B2