Water → 1-Methyl-4-piperidinemethanol

A solution of ester 21 (10.1 g, 59.0 mmol) in Et2O (40 mL) was added dropwise to a suspension of LiAlH4 (2.46 g, 64.9 mmol) in Et2O (200 mL) at 0° C. Then, the reaction mixture was allowed to warm to room temperature and was then stirred for 4 h at this temperature. Water (10 mL) was added slowly and stirring was continued for a further 30 min. The formed white precipitate was separated by filtration and washed thoroughly with Et2O (250 mL). After removal of the solvent under reduced pressure the resulting oil was purified by distillation (bp. 108° C., 14 mbar) to give alcohol 22 (6.40 g, 84%) as a colorless oil. −Rf=0.53 (CH2Cl2/MeOH, 5:1, 5% NEt3, PMA: dark blue). 1H NMR (300 MHz, CDCl3): δ=1.28 (dq, J=12.2, 3.7 Hz, 2 H, 3-Hax, 5-Hax), 1.38-1.55 (m, 1 H, 4-H), 1.68-1.79 (m, 2 H, 3-Heq, 5-Heq), 1.93 (dt, J=11.8, 2.3 Hz, 2 H, 2-Hax, 6-Hax), 2.26 (s, 3 H, NMe), 2.82-2.92 (m, 2 H, 2-Heq, 6-Heq), 3.12 (sbr, 1 H, OH), 3.46 (d, J=6.4 Hz, 2 H, CH2OH) ppm. —13C NMR (75.5 MHz, CDCl3): δ=28.8 (C-3, C-5), 37.9 (C-4), 46.3 (NMe), 55.5 (C-2, C-6), 67.4 (CH2OH) ppm. −MS (70 eV, EI): m/z (%)=129 (55) [M]+, 128 (100) [M−H]+, 112 (10) [M-OH]+, 98 (21) [M-CH2OH]+. —C7H15NO (129.20).

1. stirringstirring
2. waitwas continued for a further 30 min
3. customThe formed white precipitate was separated by filtration
4. washwashed thoroughly with Et2O (250 mL)
5. customAfter removal of the solvent under reduced pressure the resulting oil
6. distillationwas purified by distillation (bp. 108° C., 14 mbar)

ORD record

ord-28c7ddf511fe4f92a621bbd073356065

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08940784B2