Innovation of technics for producing 2-chloro-5-chloromethylpyridine

2-Chloro-5-chloromethylpyridine is the crucial intermediate of pesticides such as Imidacloprid, which is produced through the direct cyclization of 2-chloro-2-chloromethyl-4-cyanobutyraldehyde and phosphorus oxychloride.This route is widely used in industries,but toluene used as solvent lead the difficulty of recycling, and the product decomposed in distillation.So the conditions of cyclization were optimized and the crystallization was used to purify the product.Under the improved conditions,the yield of cyclization reached to 77.91 percent,and the purification yield was above 83 percent with 90 percent purity.That meets the need of industry, which reduces the using of toluene and exhaust of waste residue in distillation.