Реакция #76405

Уравнение реакции

p-toluidine

sodium nitrite

4-methyl-benzenediazonium tetrafluoroborate

Allyl cyanide

→

4-p-tolyl-but-3-enenitrile

Выход 53.0%

Растворители

fluoboric acid

ethanol

water

Условия реакции

Обработка

1. 1
   Другоеresulting in a dark brown clear solution
2. 2
   Экстракцияextracted with 2×100 ml of hexane:ethyl acetate 85:15 (v:v)
3. 3
   ПромывкаThe organic phases are washed with saturated aqueous sodium bicarbonate, water, brine
4. 4
   Сушкаdried over magnesium sulfate
5. 5
   КонцентрированиеThe light green solution is concentrated to ca 20 ml by rotary evaporation
6. 6
   Другоеto crystallize in the refrigerator
7. 7
   ФильтрацияFiltration

Методика

6.17 g (0.03 mol) of 4-methyl-benzenediazonium tetrafluoroborate (mp 105-110° C.; prepared by nitrosation of p-toluidine with sodium nitrite in aqueous fluoboric acid according to A. Roe, Org. Reactions vol V, 1949,193) are suspended in 60 ml of ethanol. Allyl cyanide (4.0 g; 0.06 mol) and palladium acetate (67 mg; 0.3 mmol) are added, and the light orange suspension is heated gently to 46° C., at which temperature a gentle evolution of nitrogen is visible. The mixture is stirred at the same temperature until the nitrogen evolution ceases (ca 3 h), resulting in a dark brown clear solution. The reaction mixture is poured into 300 ml of cold water and extracted with 2×100 ml of hexane:ethyl acetate 85:15 (v:v). The organic phases are washed with saturated aqueous sodium bicarbonate, water, brine, and dried over magnesium sulfate. The light green solution is concentrated to ca 20 ml by rotary evaporation, and allowed to crystallize in the refrigerator. Filtration yields 2.5 g (53%) of 4-p-tolyl-but-3-enenitrile as very thin, colorless leaflets, mp 60-61° C., consisting of the pure (E) isomer, as determined by 1H-NMR.

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