Potassium Cyanide → 3-Chloro-5-(trifluoromethyl)pyridine-2-carbonitrile

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Reaction Steps

3-Chloro-2-fluoro-5-(trifluoromethyl)pyridine (obtained as a by-product from the fluorine exchange reaction when converting 2,3-dichloro-5-trichloromethyl pyridine to 2,3-dichloro-5-(trifluoromethyl)pyridine) (40.0 g, 0.2 mole) was put into 270 ml of dimethyl sulfoxide and stirred while potassium cyanide (14.4 g, 0.221 mole) was spooned in over a 20-minute period. The mixture was then stirred for another 20 minutes. The temperature was held between 23° and 28° C. throughout the reaction. The mixture was poured into 600 ml of ice water and the product was extracted into hexane. The hexane was removed on a rotary evaporator. The product was treated with activated charcoal and distilled on a Vigreaux-Claisen still at 108°-110° C. at 30 mm Hg to yield 31.45 g of colorless oil with an analysis of, in percent by weight:

Provenance & Evidence