Process Improvement Of Chlorantraniliprole And Synthesis Of New Benzimidazole Compounds

This thesis is focused on optimization of certain pesticide or pharmaceuticals. Based on huge amountof references and our experiments, more economical or eco-friendly synthetic courses have been developed.The work in this thesis can be divided into the following two aspects.Firstly, we have tried many ways to optimize the synthetic technique of chlorantraniliprole, especiallythe intermediate5-chloro-2-amino-3-methylbenzoic acid. Chlorination reaction was conducted based on7-methyl-indole-2,3-dione and sulfuryl chloride. This reaction reduced the cost and increased the yield.Then open cycling reaction was conducted based on hydrogen peroxide and sodium hydroxide to get theproduct. Compared to former techniques, this synthetic routine not only reduced the cost and improved theyield but also avoid the disadvantages of the former one, such as the potential danger caused by rapidlyascending temperature. Moreover, we investigated the structure of the product by H NMR, HPLC and massspectrometry analysis, which are accordant with that reported in the references. In a word, the optimizedsynthetic routine not only reduced the cost and increased the yield but also avoid potential danger. So itpossesses practical values in industry.We have devised four steps based on maleic anhydride to get the other intermediate. And this routinecan avoid the danger aspect from sodium which is existed in former technique. Unfortunately, we failed toget the final product. And this work is under going.Secondly, click chemistry is applied into the structure modification of proton pump inhibitor. Forexample,1,2,3-triazole was introduced into the structure of proton pump inhibitor to search drugs withmore higher activity to cure canker. Azides are firstly synthesized, followed by the reaction of2-thiobenzimidazole and3-bromoprop-1-yne to get of2-(2-proynylthio)-1H-Benzimidazole. Then newbenzimidazole compounds are obtained by click chemistry. The relative easy synthetic routines providenovel ideology for studying proton pump inhibitor because they can be conduced in a shorter time withhigher yield and purity.In the process of synthesizing novel new benzimidazole compounds, the product can be obtained byusing sodium hydrogen under room temperature with water as the solvent. This reaction provided us anovel method to synthesize2-(2-proynylthio)-1H-Benzimidazole because of its many advantages, such as eco-friendliness, mild reaction condition, higher purity and yield.