Reacción #2186224

Ecuación de reacción

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

Rendimiento 70.0%

Disolventes

dioxane

dioxane

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas heated
2. 2
   Temperaturato reflux
3. 3
   Temperaturaheated
4. 4
   Temperaturaunder reflux for 6 hours
5. 5
   Extracciónextracted with dichloromethane
6. 6
   Secadothe organic phase dried over magnesium sulfate
7. 7
   Otroevaporated
8. 8
   OtroThe resulting gum was triturated with pentane

Procedimiento

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).

Fuente