Study On The Synthesis Of2-arylbenzothiazoles Under Metal-free Conditions In Water

2-Aryl benzothiazoles are very important heterocycle compounds due to theirdiverse biological and pharmacological properties, including antitumor,anti-convulsant, and anti-viral. Traditional methods, including the condensation ofo-aminothiophenols, cyclization of thioamides, cyclization of o-halogen acylanilines,trans-metal catalyzed cross coupling of benzothiazoles and aryl derivatives, havesome drawbacks repectively. Such as intensive react conditions, long react time, lowyields, generation of by-products, toxic agents and solvents.In this thesis we have developed a reaction of KI catalyzed oxidative coupling ofbenzothiazoles with aryl aldehydes using tert-butyl hydroperoxide as oxidant in waterbased on the concept of green chemistry. The oxidant, catalyst, solvent andtemperature were screened to optimize the reaction conditions. The scope ofsubstrates was investigated and a serial of2-aryl benzothiazoles were obtained. Somecontrolled experiments were also carried out to clarify the reaction mechanism. Aradical process was proposed based on the results obtained and the literaturesreported.