Study On The Synthesis Of Imidacloprid's Intermediate 2-Chlorl-5-Methyl-Pyridne

Based on the review and description of the development ten-dency of the agricultural pesticides,the necessarility of imidacloprid's existence and development has described in this paper .Then ,the experi-mental studies were carried out on the preparetion processes of 2-chlor-5- methyl-pyride intermediate, which made a solid basis for the prod-uction and the further research works.In this paper,two kind of synthesis methods were studied expe-rimentally.In the first method, 1,2-Benzene-dicarbonyl dichloride was u- sed as raw material,the preparation procedure was as follows.First,the 1,-2-Benzene-dicarbonyl dichloride was synthesized with phthalic anhydri-de and phosphorus entachloride as the materials,and GC was used as theanalysis apparatus through the experiments,the suitable synthesis condit-ions were determined finally,such as the suitable proportion between dif-ferent raw materials,the optimal reaction temperature and reaction time. Second, the 2-chlorl-5-methyl-pyridine was synthesized with O-phthal-oyl chloride and 3-methyl-pyridine- 1-oxide as raw materials .In the p-roduction process ,a well designed five factors experiment was carriedout,and the influences of the reagent- ratio, the solvent used in the reacti-on,the agent of tricing acid ,the reaction tempreture and the reaction timewere experimentally studied, and finally, the effeats of the five conditio-ns to the quality and the yield of the product were determined.In the second method,2-chlorl-5-methyl-pyridine was synthesi-zed from phosphoryl chloride and 3-methyl-pyridine -1-oxide. Throughlots of experiments,we examined the effects of the reagent-ratio,the so-lvent used in the experiment, the agent of tricing acide, the reaction tempreture and time,and the suitable reaction conditions was finally obt-ioned, and the final product was analyzed by GC , IR and MSD apparatus.Through detailed contrast between two related method, thefirst method was selected as the final production method in the industry,and it was realized in the industrial production already.