1-Benzyl 4-methyl 4-allylpiperidine-1,4-dicarboxylate → 1-Benzyl 4-methyl 4-(2-oxoethyl)piperidine-1,4-dicarboxylate

To a solution of 1-benzyl 4-methyl 4-allylpiperidine-1,4-dicarboxylate from Step B (4.45 g, 14.0 mmol) in THF (70 mL) at 0° C. was added borane-methyl sulfide complex (28.0 mL of a 2M solution in THF, 56.1 mmol). The reaction mixture was slowly warmed to ambient temperature and stirred for 16 h, then quenched with water and concentrated in vacuo. The residue was dissolved in CH2Cl2 (140 mL) and added drop wise to a solution of PCC (6.65 g. 30.8 mmol) and 4 Å molecular sieves (6.65 g) in CH2Cl2 (50 mL) at 0° C. The reaction mixture was warmed to ambient temperature and stirred for 16 h, then diluted with ether (200 mL) and filtered through a pad of celite. Additional ether was used to wash the celite. The combined organics were concentrated in vacuo to give a residue that was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:MeOH—100:0 to 95:5, to give the title compound. MS: m/z=356 (M+Na).

1. customquenched with water
2. concentrationconcentrated in vacuo
3. dissolutionThe residue was dissolved in CH2Cl2 (140 mL)
4. temperatureThe reaction mixture was warmed to ambient temperature
5. stirringstirred for 16 h
6. filtrationfiltered through a pad of celite
7. washto wash the celite
8. concentrationThe combined organics were concentrated in vacuo
9. customto give a residue that
10. customwas purified by silica gel chromatography
11. washeluting with a gradient of CH2Cl2

ORD-Eintrag

ord-92c7afabd0ac4e81bb208e090293e7a6

Quelldatensatz

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07893079B2