Chlorotrimethylsilane → 1-(Trimethylsiloxy)-1,3-butadiene

HRID 1587996Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1587996
[CH:1](=[O:5])/[CH:2]=[CH:3]/[CH3:4].C(N(CC)CC)C.[CH3:13][Si:14](Cl)([CH3:16])[CH3:15]>C1C=CC=CC=1.[Cl-].[Zn+2].[Cl-].C1(C=CC(O)=CC=1)O>[CH3:13][Si:14]([CH3:16])([CH3:15])[O:5][CH:1]=[CH:2][CH:3]=[CH2:4]

Komponenten

7

Edukt 3

HCID 6397Chlorotrimethylsilane2×HCID 8471TriethylamineHCID 447466Crotonaldehyde

Produkt 1

HCID 27242171-(Trimethylsiloxy)-1,3-butadieneAusbeute 46 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 785HydroquinoneKatalysatorHCID 3007855ZincchlorideKatalysatorHCID 241BenzeneLösungsmittel

Reaktionsbedingungen

Temperatur
25 °C

Versuchsvorschrift

To a solution of crotonaldehyde (31.8 g, 0.454 mole) and triethylamine (51.4 g, 1.1 eq) in benzene at 25° C., was added hydroquinone (0.95 g) and zinc chloride (0.75 g) rapidly with efficient stirring. This was followed by the addition of freshly distilled trimethylsilyl chloride (46 ml, 0.9 eq) over 1-2 minutes, whereupon a white precipitate rapidly formed. After stirring the mixture for 30 minutes at 25° C., a further 0.2 eq of trimethylsilyl chloride were added. The reaction was then warmed to 70° C. and stirred at this temperature for 12 hours. It was then cooled to 0° C., quenched by addition of saturated aq. NaHCO3 (75 ml), poured into a separatory funnel, and the organic layer separated. The aqueous layer was extracted with further portions of benzene (3×50 ml), the organic extracts combined, washed with 10% KHSO4, and the benzene removed in vacuo to leave a dark brown liquid. Distillation through a short Vigreaux column yielded 28.4 g (46%) of pure 1-trimethylsilyloxy-1,3-butadiene as a colorless liquid (bp 78°-80° C./68 mm Hg). 1H NMR (200 MHz, CDCl3): δ 6.66(1H,d,J=11.9 Hz), 6.35(1H,dt,J=17.1, 10.6Hz), 5.84(1H,t,J=11.4 Hz), 5.11(1H,dd,J=16.8, 1.8 Hz), 4.94(1H,dd,J=10.3, 1.8 Hz), 0.37(9H, s).

Aufarbeitung

  1. customrapidly formed
  2. temperatureThe reaction was then warmed to 70° C.
  3. stirringstirred at this temperature for 12 hours
  4. temperatureIt was then cooled to 0° C.
  5. customquenched by addition of saturated aq. NaHCO3 (75 ml)
  6. additionpoured into a separatory funnel
  7. customthe organic layer separated
  8. extractionThe aqueous layer was extracted with further portions of benzene (3×50 ml)
  9. washwashed with 10% KHSO4
  10. customthe benzene removed in vacuo
  11. customto leave a dark brown liquid
  12. distillationDistillation through a short Vigreaux column

Quellen und Nachweise

ORD-Eintrag
ord-06f31c7f5edd4b3fae3e1e7a502eba71
Quelldatensatz
uspto-grants-1993_06
Patentnummer
US05220003

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