Thionyl Chloride → 2-Chloronicotinoyl chloride

Participants

Reaction Steps

A mixture of 3.635 g (23.07 mmol) of 2-chloronicotinic acid, 20 ml of thionyl chloride and three droplets of DMF was heated under reflux for 3 hours. The reaction solution was allowed to cool, and then concentrated under reduced pressure to obtain 2-chloronicotinoyl chloride. The compound thus obtained was then dissolved in 10 ml of acetone. The solution thus obtained was then added dropwise to a solution of 1.931 g of ammonium thiocyanate in 20 ml of acetone with stirring in 5 minutes. After the termination of dropwise addition, the reaction mixture was heated to a temperature of 40° C. with stirring for 5 minutes. The resulting insoluble matters were then removed by filtration to obtain an acetone solution of 2-chloronicotinoyl isothiocyanate. To the solution thus obtained was then added dropwise a solution of 2.171 g of 3-aminopyridine in 20 ml of acetone with stirring for 5 minutes. The reaction mixture was stirred at room temperature for 17 hours, and then poured into about 1,000 ml of ice-water. The resulting crystal was collected by filtration, washed with water, and then dried under reduced pressure to obtain 3.881 g of 1-(2-chloroniconinoyl)-3-(3-pyridyl)thiourea

Provenance & Evidence