Thionyl Chloride → 2-Chloronicotinoyl chloride

Participants

Reaction Steps

A mixture of 2.486 g (15.78 mmol) of 2-chloronicotinic acid, 15 ml of thionyl chloride and two droplets of DMF was heated under reflux for 2 hours. The resulting reaction solution was allowed to cool, and then concentrated under reduced pressure to obtain 2-chloronicotinoyl chloride. The compound thus obtained was dissolved in 10 ml of acetone. The solution thus obtained was then added dropwise to a solution of 1.32 g of ammonium thiocyanate in 15 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 6 minutes to obtain a solution of 2-chloronicotinoyl isothiocyanate. To the solution thus obtained was then added dropwise a solution of 1.706 g of 3-(N-methylamino)pyridine in 10 ml of acetone with stirring in 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. The resulting crude product was recrystallized from ethanol in the presence of a 4 N ethyl acetate solution of hydrogen chloride, and then recrystallized from ethanol to obtain 2.956 g of 2-[N-methyl-N-(3-pyridyl)amino]-4H-pyrido[3,2-e]-1,3-thiazin-4-one hydrochloride.

Provenance & Evidence