Diethyl Sulfate → HCID 15017021, compound

Participants

Reaction Steps

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).

Provenance & Evidence