Dimethyl Sulfate → 1,1-Dimethylethyl 2-ethyl-6-methyl-1-piperidinecarboxylate

HRID 840687

Reaktionsgleichung

[C:1]([N:8]1[CH2:13][CH2:12][CH2:11][CH2:10][CH:9]1[CH2:14][CH3:15])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[CH3:16]N(CCN(C)C)C.[Li]C(CC)C.S(OC)(OC)(=O)=O>CCOCC.O>[C:1]([N:8]1[CH:13]([CH3:16])[CH2:12][CH2:11][CH2:10][CH:9]1[CH2:14][CH3:15])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2]

Komponenten

Reaktionsbedingungen

Temperatur: -20 °C

Versuchsvorschrift

A solution of N-Boc-2-ethylpiperidine (1.5 g, 7.0 mmol) in 28 mL of ether was cooled to −60° C. and treated with TMEDA (1.6 mL, 10.85 mmol), followed by sec-BuLi (8.5 mL, 10.85 mmol) dropwise. The mixture was slowly warmed to −20° C., stirred for 30 min, and then cooled to −78° C. The mixture was treated with a solution of dimethyl sulfate (1.6 mL, 16.69 mmol) in ether and slowly warmed to room temperature. The mixture was diluted with water and then extracted with ether. The combined extracts were dried over K2CO3 and concentrated to give a crude product as an oil which was chromatographed on silica with 5% EtOAc/hexane to give 0.88 g (59%) of the product which was homogeneous by TLC analysis. 1H NMR (250 MHz) δ3.91-3.87 (m, 1 H), 3.69-3.65 (m, 1 H), 1.83-1.41 (m, 17 H), 1.21-1.19 (d, 3 H), 0.85-0.82 (t, 3 H); 13C NMR (62.7 MHz) 155.2 (s), 78.6 (s), 53.0 (s), 46.8 (s), 28.5 (s), 27.2 (s), 26.7 (s), 22.4 (s), 20.7 (s), 13.4 (s), 11.4 (s) ppm.

Aufarbeitung

temperaturecooled to −78° C
temperatureslowly warmed to room temperature
extractionextracted with ether
dry with materialThe combined extracts were dried over K2CO3
concentrationconcentrated
customto give a crude product as an oil which
customwas chromatographed on silica with 5% EtOAc/hexane

Quellen und Nachweise

ORD-Eintrag: ord-d626dcd95d644f5fb17e8d5c02714a69
Quelldatensatz: uspto-grants-2002_04
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US06369078B1

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