Study On The Selective Removal-methyl Of4-pyridone Derivatives And α-formylation Reaction Of Pyrrole Derivatives

Two parts of studies are contented in the thesis: The study of selective removal the-methyl(s) of4-pyridones and the-formylation of pyrroles.1. The study of selective removal the-methyl of4-pyridones4-Pyridone derivatives possess potent antibacterial, antitumor, antiviral, antiinflammatory, and HIV-1integrase inhibitory activities and other bioactivities. Among them,-monosubstituted and-nonsubstituted-4-pyridones are extremely important bioactive molecules and synthetic intermediates.To the best of our knowledge, there are no reports concerning the-demethylation of2,6-dimethyl-4-pyridones, let alone the selective demethylation. Therefore, it is urgent to developconvenient and practical demethylation methods for the purpose of providing drug-like derivatives. Aftermany attempts,-monodemethylated product was observed in DMSO under O2in the presence ofFeCl3. Interestingly, in DMF, it generated,-didemethylated product.2.-Formylation of pyrroles.-Formylpyrroles are one of the most important five-membered heterocyclic synthons which are usedin the preparation of many biologically active compounds including some very important fused-ringcompounds, and highly-functional pyrrole derivatives. Traditionally,-formylpyrroles synthesized byVilsmeier-Haack, Gattermann-Koch, Reimer-Tiemann, and Duff reactions, which use unacceptableamounts of reagents and produce large quantities of side products and waste. Therefore, the preparation of-formylpyrroles under green conditions is meaningful.We develop an one pot two-step strategy to synthesize-formylpyrroles from2,3-2H-pyrroles. Firstly,the2H-pyrroles generated pyrroles via an oxidative dehydrogenation, and then the pyrroles give the desired-formylpyrroles in the presence of an iron salt, and the oxygen as the oxidant, DMSO act as both thecarbonyl source and solvent.