Study On The Synthesis Of Benzothiazole-Pyrimidine Nucleoside Hybrids And Bycyclic Pyrimidine Nucleosides

In this thesis, a series of novel benzothiazole-pyrimidine nucleoside hybrids and bicyclic pyrimidine nucleosides were synthesized. It mainly includes the following two chapters:In the first chapter, an efficient and practical route for the preparation of 2-substituted benzothiazoles and their hybrids with pyrimidine nucleoside was developed. Compared with literature methods, the procedure showed such advantages as simple procedure, mild conditions and good yields. Specific studies are as follows:1. RuCl3 catalyzed oxidative condensation of 2-aminothiophenol with aldehyde was investigated by using ionic liquid as the rection medium. Through this reaction, a series of 2-substituted benzothiazoles were synthesized with good yields.2. RuCl3 catalyzed oxidative condensation of 5-formyl pyrimidine nucleoside with 2-aminothiophenol was studied by using ionic liquid as the rection medium. Through this reaction, a series of pyrimidine nucleoside-benzothiazole hybrids were obtained smoothly.In the second chapter, a series of bicyclic pyrimidine nucleosides and benzopyran-4-ones were designed and synthesized. Specific studies are as follows:1. A series of pyrano[2,3-d]pyrimidine-2,5-dione nucleoside derivatives were synthesized via the oxidation of homopropargyl alcohols derived from 5-formyl-2'-deoxyuridine.2. A series of benzopyran-4-one derivatives were prepared via oxidation of homopropargyl alcohol derived from salicylaldehyde.In summary, a novel method for the preparation of 2-substituted benzothiazoles has been developed by using RuCl3 as catalyst. With this method, a series of benzothiazole derivatives were prepared with high efficiency. In addition, novel pyrano[2,3-d]pyrimidine-2,5-dione nucleosides were synthesized for the first time by the oxidation of homopropargyl alcohols. By using similar strategy, benzopyran-4-one derivatives are prepared efficiently via oxidation of homopropargyl alcohols derived from salicylaldehyde.