IMPROVED PROCESS FOR THE SYNTHESIS OF 2,6-DICHLORO-5-FLUORONICOTINIC ACID AND 2,6-DICHLORO-5-FLUORONICOTINOYL CHLORIDE

摘要

An improved process for the preparation of 2,6-dichloro-5-fluoronicotinoyl chloride is described where a 2,6-dihydroxy-5-fluoronicotinic acid ester is converted in one step using phosphorus oxychloride and a lithium reagent to 2,6-dichloro-5-fluoronicotinoyl chloride and subsequent basic hydrolysis affords 2,6-dichloro-5-fluoronicotinic acid.