PROCEDURES FOR THE synthesis of 2,6-DICHLOR-5-FLUORNICOTIN ACID AND 2,6-DICHLOR-5-FLUORNICOTINOYLCHLORIDE

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.