Study On The Synthesis Of Pyrrolo [1,2-α] Quinoxaline Derivatives And Spiro-Fused Pyrazolin-5-Ones

Oximes has being applied in the fields of organic synthesis,pharmacochemistry and biochemistry,and O-acetyl oximes have been widely used as the key intermediate of various organic reactions in the synthesis,In this thesis,we developed a practical approach to Pyrrolo[1,2-α]quinoxalines and spiro-fused pyrazolin-5-ones which are very important nitrogen heterocyclic compounds by using O-acetyl oximes as the substrates.1.The synthesis of pyrrolo[1,2-α]quinoxalinesPyrrolo[1,2-α]quinoxalines are very important heterocyclic compounds owing to the broad biological activities,which possess a wide variety of interesting biological activities.For instance,the alternative pyrrolo[1,2-α]quinoxaline derivatives have been exhibited to behave as exhibiting anti-HIV,antiparasitic,anticaking agenter antipsychotic,as well as exhibiting antiproliferative and antitumor activities.Pyrrolo [1,2-α]quinoxalines can be assembled by a one-pot multicomponent reaction or the cyclization of quinoxaline derivatives via a single or multi-step reaction process,the reactions provide an synthetic strategy of diversity.In this thesis,alternative route has been developed for the new synthesis of pyrrolo[1,2-α]quinoxalines from our efforts towards the Fe(III)-catalyzed intramolecular directed aromatic C(sp2)-N cross-coupling reaction of 1-(N-arylpyrrol-2-yl)ethanone O-acetyl oximes.in acetic acid glacial,by using Fe(acac)3 as catalyst under the heating condition.This reaction occurs under mild conditions and provides rapid,new and effective,highly modular and flexible access to a wide range of fused pyrrolo [1,2-α]quinoxaline ring systems.2.The synthesis of spiro-fused pyrazolin-5-onesPyrazolones are very important intermediates and products in analytical,dye,biological and pharmaceutical chemistry owing to the broad biological activities and structural complexity.Nowdays,numerous effective methods have been built for the structure of pyrazolones,however a review of the bibliographical reference in this area revealed a lack of robust alternatives for synthesis of the spiro-fused pyrazolin-5-ones,despite potential applications are included in organic synthesis and pharmaceutical chemistry.we present our efforts toward the copper-catalyzed intramolecular directed N-N bond formation of cyclopropyl O-acetyl oximes for the synthesis of spiro-fused pyrazolin-5-ones,this reaction so as to builds the effective and practical methods,In addition,it will be the composite foundation of the following researches about spiro-fused pyrazolin-5-ones compounds.