Dimethylformamide → Ethyl 2-(3-((trimethylsilyl)ethynyl)pyrazin-2-yl)acetate
Reaktionsgleichung
Cl[C:2]1[C:3]([CH2:8][C:9]([O:11][CH2:12][CH3:13])=[O:10])=[N:4][CH:5]=[CH:6][N:7]=1.CN(C=O)C.[CH3:19][Si:20]([C:23]#[CH:24])([CH3:22])[CH3:21]>Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Cu]I.C(N(CC)CC)C>[CH3:19][Si:20]([C:23]#[C:24][C:2]1[C:3]([CH2:8][C:9]([O:11][CH2:12][CH3:13])=[O:10])=[N:4][CH:5]=[CH:6][N:7]=1)([CH3:22])[CH3:21]Komponenten
Edukt 3
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 3
Reaktionsbedingungen
- Temperatur
- 90 °C
Versuchsvorschrift
A mixture of the ethyl 2-(3-chloropyrazin-2-yl)acetate (I99) (0.410 g, 2.04 mmol), DMF (6 mL), triethylamine (2 mL), bis(triphenylphosphine)palladium(II) chloride (72 mg, 5 mol %) and copper(I) iodide (19 mg, 5 mol %) in a Schlenk tube was degassed with three vacuum/nitrogen cycles, then trimethylsilylacetylene (0.866 mL, 6.13 mmol) was added under nitrogen. The tube was flushed with nitrogen, sealed and heated to 90° C. After 18 hours the mixture was cooled and poured into water (50 mL). Saturated ammonium chloride (50 mL) was added, and the mixture was extracted with diethyl ether (3×100 mL). The combined ether phases were washed with brine, dried (sodium sulphate) and evaporated. The residue was chromatographed (40 g silica cartridge, 0-30% ethyl acetate/petroleum benzine 40-60° C.) to give the title compound (I100) (0.386 g, 72% yield) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 8.47-8.41 (m, 2H), 4.20 (q, J=7.1 Hz, 2H), 4.05 (s, 2H), 1.26 (t, J=7.1 Hz), 0.28 (s, 9H). LCMS Method C: rt 6.20 min; m/z 263.1 [M+H]+.
Aufarbeitung
- customwas degassed with three vacuum/nitrogen cycles
- customThe tube was flushed with nitrogen
- customsealed
- temperatureAfter 18 hours the mixture was cooled
- additionpoured into water (50 mL)
- additionSaturated ammonium chloride (50 mL) was added
- extractionthe mixture was extracted with diethyl ether (3×100 mL)
- washThe combined ether phases were washed with brine
- dry with materialdried (sodium sulphate)
- customevaporated
- customThe residue was chromatographed (40 g silica cartridge, 0-30% ethyl acetate/petroleum benzine 40-60° C.)
Quellen und Nachweise
- ORD-Eintrag
- ord-b745b2b92b09402faf9d7e680f5c6a8b
- Quelldatensatz
- uspto-grants-2015_04
- Patentnummer
- US09012461B2
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