反应详情

温度

3 °C

Cinnamoyl acetonitrile (5.1 g; 0.03 mol) is dissolved in 50 ml of acetic acid. 10 ml of H2O are added and the mixture is cooled to 3° C. in an ice/salt bath. Partial precipitation occurs, but the mixture remains well stirrable. Sodium nitrite (4.14 g; 0.06 mol) is added by portions over 10 min, keeping the temperature between 3 and 5° C. Complete solution is observed during addition, but precipitation occurs again towards the end. The mixture is then stirred at 0° C. for 1.5 h. The mixture is diluted with 100 ml of iced water with stirring, the light ochre precipitate is filtered, and washed with ca 100 ml of water. The humid cake is redissolved in ether (100 ml), washed with water, brine and dried over magnesium sulfate. Rotary evaporation and drying affords 2-hydroxyimino-3-oxo-5-phenyl-pent-4-enenitrile (4.7 g; 78%) as a dark yellow solid (mp 144-145° C. dec) which is used without further purification in the next reaction step.

1. customPartial precipitation
2. customthe temperature between 3 and 5° C
3. additionComplete solution is observed during addition, but precipitation
4. stirringwith stirring
5. filtrationthe light ochre precipitate is filtered
6. washwashed with ca 100 ml of water
7. dissolutionThe humid cake is redissolved in ether (100 ml)
8. washwashed with water, brine
9. dry with materialdried over magnesium sulfate
10. customRotary evaporation
11. customdrying