Réaction #2186224

Équation de réaction

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

Rendement 70.0%

Solvants

dioxane

dioxane

Conditions de réaction

Traitement

1. 1
   Températurewas heated
2. 2
   Températureto reflux
3. 3
   Températureheated
4. 4
   Températureunder reflux for 6 hours
5. 5
   Extractionextracted with dichloromethane
6. 6
   Séchagethe organic phase dried over magnesium sulfate
7. 7
   Autreevaporated
8. 8
   AutreThe resulting gum was triturated with pentane

Mode opératoire

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).

Source