Reaktion #55080

Reaktionsgleichung

hydroxylamine

sodium methylate

3,4-dichlorobenzylthioacetic acid

H2SO4

dichloroethane

→

stated product

Ausbeute 75.0%

3,4-Dichlorobenzylthioaceto-hydroxamic acid

Ausbeute 75.0%

Lösungsmittel

methanol

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture is heated
2. 2
   Temperaturunder reflux for 4 hours
3. 3
   Waschenwashed with water and with dilute bicarbonate solution
4. 4
   Sonstigedried
5. 5
   SonstigeThe mixture is evaporated in vacuo
6. 6
   SonstigeAfter leaving the reactants in contact overnight
7. 7
   Sonstigethe mixture is evaporated to dryness in vacuo
8. 8
   Filtrationthe mixture is filtered over charcoal
9. 9
   Sonstigethe filtrate is precipitated with 3 N HCl
10. 10
    Extraktionthe product is extracted with ether
11. 11
    Sonstigethe extract is dried
12. 12
    Sonstigeevaporated
13. 13
    Sonstigethe product is crystallised in diisopropyl ether

Vorschrift

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.

Quelle