Reaktion #74771

Reaktionsgleichung

2-chlorobenzaldehyde

acetone

NaOH

HCl

→

4-(2-chlorophenyl)-but-3-ene-2-one

Ausbeute 60.0%

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled in an ice bath
2. 2
   Sonstigeis kept below 40° C
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Extraktionextracted with benzene
5. 5
   workup.ADDITION0.5 g of toluene-sulfonic acid is added to the benzene solution
6. 6
   Temperaturthe mixture refluxed under a water separator
7. 7
   SonstigeA total of 6 ml of water is collected
8. 8
   TemperaturThe mixture is cooled
9. 9
   workup.STIRRINGshaken with bicarbonate
10. 10
    Trocknendried (Na2SO4)
11. 11
    Sonstigeevaporated
12. 12
    workup.DISTILLATIONDistillation

Vorschrift

A solution of 200 g (1.4 mole) of 2-chlorobenzaldehyde in 500 ml of acetone is treated with 200 ml of water, cooled in an ice bath, then treated with 40 ml of 10% NaOH by drops. The mixture is kept below 40° C. After the addition is complete the mixture is stirred at 25° C. for 1.5 hours, then acidified with 10% HCl. The mixture is diluted with water and extracted with benzene. 0.5 g of toluene-sulfonic acid is added to the benzene solution and the mixture refluxed under a water separator. A total of 6 ml of water is collected. The mixture is cooled, shaken with bicarbonate, dried (Na2SO4), and evaporated. Distillation gives 150 g (60%) of 4-(2-chlorophenyl)-but-3-ene-2-one, b.p. 106°-120° C. @ 1 mm Hg.

Quelle