Hydrochloric Acid → (R)-4-benzyl-2-methylmorpholine hydrochloride

Temperatur

0 °C

To a stirred solution of (R)-1-(benzyl(2-hydroxyethyl)amino)propan-2-ol (110 g, 525.60 mmol) in dioxane (500 mL) under nitrogen, potassium hydroxide powder (88 g, 1576.80 mmol) and tris(2-(2-methoxyethoxy)ethyl)amine (1.681 mL, 5.26 mmol) were successively added. The mixture was cooled to 0° C. and a solution of 4-methylbenzene-1-sulfonyl chloride (105 g, 551.88 mmol) in dioxane (500 mL) was added dropwise. The reaction mixture was stirred at 0° C. for 45 min then at room temperature for an additional 4 h. The mixture was filtered and filtrate evaporated. The residue was dissolved in DCM and purified on silica, eluting with 25% of EtAc in DCM. The solvents were evaporated to afford an oil which was diluted with EtAc (250 mL). A solution of 4N HCl in dioxane (0.066 L, 262.8 mmol) was then added dropwise under stirring. After 30 min, the formed solid was collected by filtration, washed with diethyl ether and dried to afford (R)-4-benzyl-2-methylmorpholine hydrochloride (40 g, 33%) as a white solid. Proton NMR Spectrum: (DMSO-d6): 1.09 (d, 3H), 2.67-2.77 (m, 1H), 2.93-3.04 (m, 1H), 3.14-3.23 (m, 2H), 3.83-4.00 (m, 3H), 4.29-4.34 (m, 2H), 7.43-7.49 (m, 3H), 7.60-7.68 (m, 2H), 11.62 (bs, 1H).

1. waitat room temperature for an additional 4 h
2. filtrationThe mixture was filtered
3. customfiltrate evaporated
4. dissolutionThe residue was dissolved in DCM
5. custompurified on silica
6. washeluting with 25% of EtAc in DCM
7. customThe solvents were evaporated
8. customto afford an oil which
9. additionwas diluted with EtAc (250 mL)
10. stirringunder stirring
11. waitAfter 30 min
12. filtrationthe formed solid was collected by filtration
13. washwashed with diethyl ether
14. customdried

ORD-Eintrag

ord-cf6a78ed22374a51968fffbda444d0f6

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08530470B2