Study On The Synthesis Of Two Kinds Of Dipyrrole Dissullfide Derivatives By Using β-ketothioamides

Pyrrole is widely known as a biologically active scaffold which possesses a diverse nature of activities. The combination of different pharmacophores in pyrrole ring system has led to the formation of more activecompounds. Pyrrole containing analogs are considered as a potential source of biologically activecompounds that contains a significant set of advantageous properties and can be found in many natural products. The marketed drugs containing a pyrrole ring system are known to have many biologicalproperties such as antipsychotic, β-adrenergic, antagonist, anxiolytic, anticancer(leukemia, lymphoma and myelofibrosis etc.), antibacterial, antifungal, antiprotozoal, antimalarial. Due to the diversity of these analogs in the therapeutic response profile, many researchers have been working to explore this skeleton to its maximum potential against several diseases. Attempts have been made to disclose various tactical approaches to synthesize pyrrole and pyrrolecontaining analogs.Modern methods for the formation of S-S bonds are required for the synthesis of many biologically active compounds involved in chemical and biological processes. There are many biologically active peptides and peptide mimetics that possess S-S bonds. Compounds containing S-S linkage have been used for the preparation of dynamic combinatorial libraries, catenanes, macrocycles, carceplexes, dendrimers, rotaxanes and micelles. These examples demonstrate the wide applications of di-sulfides and show that the synthesis of S-S bonds is a pivotal transformation in modern research.In the first chapter, β-Ketothioamides(KTAs) are introduced for its rapid construction of various heterocycliccompounds in recent years. Subsequently, focuses on the synthesis and applications of polypyrrole and disulfide.In the second chapter, a novel one-pot approach for synthesizing dipyrrole disulfides derivatives by the reaction of β-ketothioamides, arylglyoxals, withethyl cyanacetate are described. Optimization of the reaction conditions was carried out from the aspects of the catalyst, the solvent, reaction temperature. The optimized conditions for this reaction are DABCO(0.5 equiv) as promoter, EtOH as the solvent at 50°C. This easy purification makes this methodology facile, practical, and rapid to execute, the solid product was filtered, washed with EtOH to give the pure product.In the third chapter, a novel one-pot approach for synthesizing dipyrrole disulfides derivatives by the reaction of β-ketothioamides and withethyl cyanacetate were described, but having different reaction mechanism. Optimization of the reaction conditions was carried out from the aspects of the catalyst, the solvent, reaction temperature. The optimized conditions for this reaction are pyridine(1.0 equiv) as promoter, EtOH as the solvent at 50°C. This easy purification makes this methodology facile, practical, and rapid to execute, the solid product was filtered, washed with EtOH to give the pure product.The structures of all synthesized compounds were characterized by 1H NMR, 13 C NMR, and HRMS. Furthermore, crystals of compounds 5 and 6 were developed to determine their precise spatial configurations.