How is 2-Chloronicotinoyl chloride (CAS: 49609-84-9) typically synthesized?

2-Chloronicotinoyl chloride is often synthesized by reacting nicotinic acid with thionyl chloride in the presence of an appropriate base, such as pyridine. This process involves the displacement of the hydroxyl group in nicotinic acid by chlorine, followed by the release of hydrogen chloride. The reaction is typically carried out in an inert organic solvent like dichloromethane under mild conditions, ensuring high yield and selectivity.