Thionyl Chloride → 1-(2,6-Dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfenyl-5-(pyrazin-2-ylmethylamino)pyrazole-3-carbonitrile

Participants

Reaction Steps

Into 5.0 ml of 1,2-dichloroethane were suspended 1.725 g (10.0 mmol) of potassium trifluoromethanesulfinate, 895 mg (4.1 mmol) of dimethylamine p-toluenesulfonate, 951 mg (5.0 mmol) of p-toluenesulfonic acid monohydrate, and then 1.506 g (12.6 mmol) of thionyl chloride was added under ice-cooling. After 3 hours of stirring at room temperature, 1.03 g (2.5 mmol) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(pyrazin-2-ylmethylamino)pyrazole-3-carbonitrile was added thereto, and the mixture was warmed to 40° C. and stirred for 5 hours. The reaction mixture was neutralized with saturated aqueous sodium hydrogen carbonate solution and then extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure and the resulting oil was purified to isolate 487 mg (yield 38%) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfenyl-5-(pyrazin-2-ylmethylamino)pyrazole-3-carbonitrile.

Provenance & Evidence