Study On The Synthesis Process Of Iodine-containing Pyrazine-based Fine Chemicals

Iodine as the rare resource in the world occupies an important position in organic reactions and plays an extremely important role in the national economy.China's iodine resource is relatively scarce.The fine chemicals of iodine-containing pyrazines belong to the high value-added industry of iodine-containing drugs and pesticides.The development of iodine-containing pyrazine compounds can not only improve the utilization rate of iodine resource,but also effectively extend the organic iodine chemical industry chain.Organic iodine has a wide range of uses in the fields of medicines and pesticides.Pyrazine compounds are rare in domestic researches and are important intermediates for drug synthesis.Iodine-containing pyrazine compounds are relatively few in domestic and foreign research reports.Over time,the fine chemicals of iodine-containing pyrazines have gradually emerged in medicines and pesticides,having become the focus of researches.This project mainly synthesizes 10-15 iodine-containing pyrazine compounds selected by market researches.While designing its process route,it is also necessary to reduce costs and increase yields as much as possible,At the same time,the route optimization design of the compounds reported in the existing synthetic route is carried out,which lays the foundation for the future pilot scale-up research.The iodination methods of iodine-containing pyrazine compounds include the diazo iodination method,the iodine substitution reaction method,the n-butyl lithium method,the halogen exchange iodination method and the NIS iodination reaction method.Considering the advantages and disadvantages of the above various iodination methods,this project mainly adopts the NIS iodination and iodine substitution reaction methods to perform iodine substitution on the para or ortho position of the amino group.Then the synthesized amino-containing iodopyrazine compounds are selected to convert the amino group into the halogen atom through diazotization reaction to synthesize new iodine-containing pyrazine compounds.This project uses some simple pyrazine compounds and organic reagents as raw materials,introduces some specific groups,and finally introduces iodineatoms at specific positions of the pyrazine rings to obtain fine intermediate products of iodine-containing pyrazines.The main focus of the work is to open up the synthetic route of fine chemicals of iodine-containing pyrazines.By referring to relevant literatures and the progress of comprehensive experiments,the suitable synthetic route is designed and its technology is optimized.The synthesized target compounds are characterized by MS,~1H NMR and IR,and the characterization results show that the compounds have the correct structures.