Research On The Green Oxybrominationand Its Applicaition In The Synthesis Of The Intermediate Of Trimethoprim

This dissertation consists of two parts:(a)reaserch on the green and high atom-economy method of the oxybromination in water.(b)application of the green oxybromination in synthesis of 3,4,5-trimethoxy benzaldehyde(TMB).In the first chapter,we presented the review of the progress of the oxybromination(not aerobic).An improved method of oxybrominaion for arenes using hydrogen peroxide as an oxidant has been developed.In the second chapter,we have developed an aerobic oxybromination of aromatic compounds in water.Only 1%mol copper nitrate is used as an oxdative catalyst and hydrobromic acid is used as a brominating agent.Various arenes can be easily brominated in this system with high atom economy and high selectivity.The difference of chemo-and regio-selectivity among the various substrates has also been discussed.In the third chapter,we reported the metal-free aerobic oxybromination in water using only 10%mol 2-methyl pyridinium nitrate as a catalyst.Several aromatic compounds show great reactivity in this reaction.The role of the catalyst in this system has also been studied.The fourth chapter,the development of synthesis of 3,4,5-trimethoxy trimethoxy benzaldehyde(TMB)was introduced.And the oxybromination method has been used for the first step of the sythesis of TMB.We also optimize the second and third step to obtain good results.