Reaktion #45717

Reaktionsgleichung

tributyl(1-ethoxyvinyl)tin

6-Bromo-2-(dimethylamino)-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

→

solid

Ausbeute 66.0%

6-(1-Ethoxyvinyl)-2-(dimethylamino)-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

Ausbeute 66.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturby heating
2. 2
   Temperaturunder reflux for 3 days
3. 3
   SonstigeThe insoluble matter was removed by filtration through Celite
4. 4
   Waschenby washing with ethyl acetate
5. 5
   SonstigeThe solvent was evaporated away under reduced pressure
6. 6
   Sonstigethe resulting residue was purified by silica gel column chromatography (dichloromethane:hexane=1:2 to 2:3 to 9:1 to dichloromethane:methanol=200:1)

Vorschrift

6-Bromo-2-(dimethylamino)-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-168) (0.80 g, 2.68 mmol) was dissolved in toluene (25 ml), then tributyl(1-ethoxyvinyl)tin (1.30 ml, 3.85 mmol), 2,6-di-tert-butylcresol (12 mg, 0.05 mmol) and bis(triphenylphosphine)palladium(II) dichloride (0.10 g, 0.14 mmol) were added followed by heating under reflux for 3 days. The insoluble matter was removed by filtration through Celite, followed by washing with ethyl acetate. The solvent was evaporated away under reduced pressure, and the resulting residue was purified by silica gel column chromatography (dichloromethane:hexane=1:2 to 2:3 to 9:1 to dichloromethane:methanol=200:1) to obtain a brown solid (0.51 g, 66%).

Quelle