Reacción #56459

Ecuación de reacción

sodium chloroacetate

2,4-dichlorobenzylchloride

thiourea

NaOH

→

product

Rendimiento 88.7%

2,4Dichlorobenzylthio-acetic acid

Rendimiento 88.7%

Disolventes

water

water

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture is heated to 50°-60° C.
2. 2
   TemperaturaThe mixture is heated
3. 3
   Temperaturaunder reflux
4. 4
   Temperaturaboiling is maintained for 15 minutes
5. 5
   TemperaturaThe mixture is cooled
6. 6
   TemperaturaThe mixture is again heated
7. 7
   Temperaturaunder reflux for 30 minutes
8. 8
   Temperaturacooled
9. 9
   Otroat 60°-70° C
10. 10
    TemperaturaThe whole is then heated
11. 11
    Temperaturaunder reflux for 30 minutes
12. 12
    Temperaturacooled
13. 13
    Filtraciónfiltered
14. 14
    Otrothe precipitate obtained
15. 15
    Filtraciónis filtered off the redissolved cold in dilute sodium bicarbonate solution
16. 16
    Lavadothis solution is washed with methylene chloride
17. 17
    Filtraciónfiltered

Procedimiento

15.2 g (0.2 mol) of thiourea in 100 ml of water are introduced into a 1 liter 3-necked flask. The mixture is heated to 50°-60° C. and 39.1 g (0.2 mol) of 2,4-dichlorobenzylchloride are introduced in a single operation. The mixture is heated under reflux and boiling is maintained for 15 minutes; the solution becomes limpid. The mixture is cooled and a solution of 32 g (0.8 mol) of NaOH in 50 ml of water is introduced dropwise at about 60° C. The mixture is again heated under reflux for 30 minutes, cooled and a solution of about 0.28 mol of sodium chloroacetate (obtained by neutralising 26.46 g of chloroacetic acid in 200 ml of water with 23.52 g of NaHCO3) is introduced, dropwise, at 60°-70° C. The whole is then heated under reflux for 30 minutes, cooled, filtered and acidified with 3 N HCl; the precipitate obtained is filtered off the redissolved cold in dilute sodium bicarbonate solution, and this solution is washed with methylene chloride, filtered and again acidified. 41.7 g (yield: 83 %) of product are thus collected. Instantaneous melting point: 72°-73° C.

Fuente