Reacción #55080

Ecuación de reacción

hydroxylamine

sodium methylate

3,4-dichlorobenzylthioacetic acid

H2SO4

dichloroethane

→

stated product

Rendimiento 75.0%

3,4-Dichlorobenzylthioaceto-hydroxamic acid

Rendimiento 75.0%

Disolventes

methanol

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture is heated
2. 2
   Temperaturaunder reflux for 4 hours
3. 3
   Lavadowashed with water and with dilute bicarbonate solution
4. 4
   Otrodried
5. 5
   OtroThe mixture is evaporated in vacuo
6. 6
   OtroAfter leaving the reactants in contact overnight
7. 7
   Otrothe mixture is evaporated to dryness in vacuo
8. 8
   Filtraciónthe mixture is filtered over charcoal
9. 9
   Otrothe filtrate is precipitated with 3 N HCl
10. 10
    Extracciónthe product is extracted with ether
11. 11
    Otrothe extract is dried
12. 12
    Otroevaporated
13. 13
    Otrothe product is crystallised in diisopropyl ether

Procedimiento

20.2 g (0.08 mol) of 3,4-dichlorobenzylthioacetic acid are esterified with 10 ml of methanol, 0.6 ml of concentrated H2SO4 and 100 ml of dichloroethane. The mixture is heated under reflux for 4 hours, washed with water and with dilute bicarbonate solution, and dried. The mixture is evaporated in vacuo. The oily residue, in methanol, is treated with a solution of hydroxylamine (0.1 mol) in the presence of 0.18 mol of sodium methylate. After leaving the reactants in contact overnight, the mixture is evaporated to dryness in vacuo, the residue is taken up in water, the mixture is filtered over charcoal and the filtrate is precipitated with 3 N HCl, the product is extracted with ether, the extract is dried and evaporated and the product is crystallised in diisopropyl ether. 15 g of the stated product are obtained (yield 71%). Melting point: 75°-76° C.

Fuente