Study On The Synthesis Of Furo[3,2-b]indole Derivatives And Polysubstituted Pyridones

This dissertation aims at the development of new synthetic methodologies of furo[3,2-b]indoles andpoly-substituted pyridones.1The synthesis of furo[3,2-b]indolesFuroheterocycles is the structural nucleus of several natural products with pronounced biologicalactivities. Furo[3,2-b]indoles, one kind of Furoheterocycles, are of vital medicinal value. They showedpronounced pharmacological activities such as antiallergy, anti-inflammatory, potent analgesic andantipyretic activities. In addition, they are also key intermediates for the synthesis of several naturalproducts.Although there are many reports concerning the synthesis of furo[3,2-b]indoles andfuro[2,3-b]benzofurans, most of them have disadvantages such as complicated process, limited substrates,harsh conditions and low yields. Thus it can be seen that the mild and efficient simultaneous preparation ofthese cyclic systems, particularly via new strategies, remains an important and expectant objective. In thepresent research, a new method has been developed for the synthesis of furo[3,2-b]indoles from a series ofo-propargylaminoacetophenones via a novel Ag（I）-mediated intramolecular1,3-dipolars cycloadditionreactions under microwave irradiation conditions.2The synthesis of poly-substituted pyridones.4-Pyridone derivatives are identified as antibacterial activities, antitumor activities, antiviral activities,antiinflammatory activities and other bioactivities. They are also important intermediates in the organicsynthesis and the key structure of some natural products. Acetoacetarylamides and their derivatives areimportant reagents in organic synthesis. They have more active sites and a wide range of applications,especially in the dye industry and pharmaceutical chemistry. To date, just few literatures focus on the directsynthesis of poly-substituted4-pyridones from acetoacetarylamides. In the present work, a convenientone-pot process has been developed for the synthesis of a variety of biologically potent poly-substituted4-pyridones via self-condensation of industrialized N-aryl acetoacetamides in the presence of sole Na2S2O8,during which, a novel N to C1,3-acyl migration should be involved. All products were constructedefficiently in a single step from the readily available acyclic precursors. Also, the simple operation with satisfactory yields, non-acidic and non-alkaline condition, metal catalyst-free, a relative broad range ofsubstrates, and readily availability of catalyst （Na₂S₂O₈） and substrates make this as a valuable addition toexisting methods.