Studies On The Synthesis Of Benzisothiazole And Its Derivatives Based On The Phenylsulfoxide Compounds

Benzoisothiazole compounds as a stable organic chemical structure of the skeleton has a very important research value,benzisothiazole compounds because of its special structure with a variety of biological activity,can be used for synthesizing of pesticides,antipsychotic drugs,materials,etc.For example:the United States Pfizer pharmaceutical companies developed anti-schizophrenia drug ziprasidone,benzisothiazole-substituted piperazine atypical antipsychotics,compared with the traditional antipsychotics the size of side effects significantly.Therefore,the synthesis of a variety of benzoisothiazole compounds have important theoretical significance and practical value.Chiral induction and construction of chiral 6-membered ring carbenes induced by chiral t-butylxynamide have been the focus of our research group.In this paper,we first design and synthesize a series of sulfoxides,and the S-N bond was constructed very efficiently and conveniently by the removal of the tert-butyl group in the phenyl tert-butyl sulfoxide compounds by the NBS and acid conditions.Compared with the traditional method,the method has the advantages of mild reaction condition,high conversion rate,no metal catalysis and so on.In addition,our experimental evidence strongly supported an all heteroatom Wittig-equivalent transformation process for the formation of the final products.The main work of this paper includes the following two aspects:First,Synthesis of phenylsulfoxides:with aryl tert-butyl sulfoxide as the nucleus,we designed and synthesized intermediates of phenyl sulfoxide compounds with different substituents.All of the compounds were characterized by ¹HNMR,¹³CNMR spectra,and some new compounds were characterized by HR-MS and then used to synthesize benzoisothiazole compounds.Second,The synthesis of benzoisothiazole compounds:the traditional S-N bond of benzoisothiazole compounds are generally harsh to construct.The newest research results of the group have been used for this paper.The S-N bond of benzoisothiazole compounds was successfully synthesized under the conditions of NBS and acid.Compared with the traditional method,the method has the advantages of high efficiency,convenience,mild reaction condition and so on.It is a supplement to traditional synthetic benzisothiazole method.A series of benzisothiazoles have been synthesized by this method.All of the compounds have been characterized by ¹HNMR,¹³CNMR spectra,and some new compounds have been characterized by HR-MS.