New Synthesis Method of 2-Chloronicotinic Acid

2-Chloronicotinic acid was synthesized from ethyl cyanacetate by the reactions of chlorination;cyclization and hydrolysis.The reaction conditions were optimized.Compared to the classical literature method,the rate of double-chlorinated and single-chlorinated product is controlled in within the ratio of(48∶50)~(50∶48).In the process the redistribution of chlorine was eliminated and toluene-sodium methoxide was used as the reaction solvent of Michael addition.Another improvement was the two-step reactions used in cycllization.These optimizations can make the control of reaction easier and more concise.The total product yield is increased to 66.5%.