Study On Synthesis Of Benzothiazines Compounds Based On Inorganic Sulfides

Benzothiazines are key functional molecules,which widely present in a myriad of natural products and biologically active compounds.As the important derivatives of benzothiazines,benzothiazinones show good biological activities,such as,antipsychotic,antituberculosis activities.Therefore developing simple and efficient methods for the synthesis of benzothiazinones are of great value.Recently,inorganic sulfides,as stable and easily available sulfur sources,have been widely used for the synthesis of sulfur-heterocyclic compounds.In this paper,we have summarized the recent research and developed an efficient and practical procedure for the synthesis of benzothiazinones compounds,with potassium sulfide as sulfur sources and copper as catalyst.Chapter one:a short review,the development of synthetic methods about benzothiazines and benzothiazinones.Chapter two:study on copper-catalyzed synthesis of 2-benzylbenzo[b]thiazinones.2-Iodophenylcinnamamides and potassium sulfide have reacted under copper-catalyst and DBU,the reaction proceeds via oxidization,electrophilic addition,followed by dehydrogenation and reduction to give 2-benzyl benzo[b]thiazinones.Chapter three:study on copper-catalyzed synthesis of 2-benzylidenebenzo[b]thiazinones.Based on the research of 2-benzyl benzo[b]thiazinones,we find that 2-benzylidenebenzo[b]thiazinones were obtained in good yields without the addition of DBU.The experiment suggested that the reasonable mechanisms were radical process.