3,5-Dichloro-2-cyanopyridine

15177-57-8

7677-24-9

85331-33-5

General procedure for the synthesis of 2-cyano-3,5-dichloropyridine from 3,5-dichloropyridine 1-oxide and trimethylcyanosilane: 21.8 mL (0.174 mol) of trimethylcyanosilane and 14.6 mL (0.158 mol) of dimethylcarbamoyl chloride were sequentially added to 26 g (0.158 mol) of 3,5-dichloropyridine 1-oxide in an 80-mL dichloromethane solution. The reaction mixture was stirred at room temperature for 48 hours. After the reaction was completed, 100 mL of 10% aqueous NaHCO3 solution was added and stirred vigorously for 10 minutes. After separating the organic and aqueous phases, the aqueous phase was extracted once with dichloromethane. All organic phases were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane as eluent. The target fraction was collected, concentrated and recrystallized from a small amount of methanol to give 11 g (40.2% yield) of 2-cyano-3,5-dichloropyridine with a melting point of 102 °C. The target fraction was collected, concentrated and recrystallized from a small amount of methanol.