Reaktion #2186224

Reaktionsgleichung

potassium hydrogensulfate

sodium hydride

1-(2,6-dichloro-4-trifluoromethylphenyl)-5-hydroxy-4-trifluoromethylthio-1H-pyrazole-3-carbonitrile

diethyl sulfate

→

1-(2,6-dichloro-4-trifluoromethylphenyl)-5-ethoxy-4-trifluoromethylthio-1 H-pyrazole-3-carbonitrile

Ausbeute 70.0%

Lösungsmittel

dioxane

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturto reflux
3. 3
   Temperaturheated
4. 4
   Temperaturunder reflux for 6 hours
5. 5
   Extraktionextracted with dichloromethane
6. 6
   Trocknenthe organic phase dried over magnesium sulfate
7. 7
   Sonstigeevaporated
8. 8
   SonstigeThe resulting gum was triturated with pentane

Vorschrift

To a stirred suspension of sodium hydride (0.41 g, 60%, 10.3 mmol) in dioxane (150 ml) was added a solution of 1-(2,6-dichloro-4-trifluoromethylphenyl)-5-hydroxy-4-trifluoromethylthio-1H-pyrazole-3-carbonitrile (4.00 g, 8.53 mmol) in dioxane (50 ml). After gas evolution had ceased the mixture was heated to reflux and diethyl sulfate (1.25 ml, 9.47 mmol) added, and then heated under reflux for 6 hours. The cooled mixture was acidified with aqueous potassium hydrogensulfate (5%), extracted with dichloromethane, and the organic phase dried over magnesium sulfate and evaporated. The resulting gum was triturated with pentane to give 1-(2,6-dichloro-4-trifluoromethylphenyl)-5-ethoxy-4-trifluoromethylthio-1 H-pyrazole-3-carbonitrile (2.68 g, yield 70 %) as off-white crystals, mp 106° C., 1H NMR (CDCl3): 1.36 (t, 3H, CH3), 4.71 (q, 2H, OCH2), and 7.76 (s, 2H, Ar—H).

Quelle