Studies On The Synthesis And Applications Of 1-Aryl-2-Arylamino-Ethanones

Heterocyclic chemistry is an important part of organic chemistry. About one third of all theorganic compounds are heterocyclic compounds. The vast number of bioactive natural products based on heterocyclic compounds, such as nucleic acid, vitamin, antibiotic, hormone, pigment, alkaloid, are very important in the area of natural product and pharmaceutical chemistry.Nitrogen containg heterocyclic compounds are an important subset of heterocyclic compounds, But the important brand of heterocyclic compounds is, which are extensively used as the intermediate of medicine, agrochemicals, dyestuffs and other fine chemicals. Therefore, the design and synthesis of heterocyclic compounds having some bioactivities attract more and more chemists and pharmacologists for doing research in this field.Green chemistry is also called environmentally benign chemistry, Environally Friendly Chemistry or Clean Chemistry. Green chemistry is utilizing chemical technics and measures to reduce or cleanup the production and usage of those chemical material, activator, impregnant, reagent, outcome and outgrowth which will do harms to human health, community safety and environment. The goal of Green chemistry is the venomousness and harmful substances are no longer being used and waste will no longer exist and need treatment. The green chemistry can prevent pollution from its headstream.Developments of new basic reactions and new synthetic methods are the basis for the innovation and advance of organic chemistry. Based on the research achievement of our group, my thesis starts from the synthesis of new substracts through synthetic design, aim to develop novel nitrogen containg heterocyclic compounds and new synthetic methods for interesting nitrogen containg heterocyclic compounds, particularly, developing a new synthetic strategy to provide a general and simple route to nitrogen containg heterocyclic ring systems. At the same time, starting from theα-arylamino ketones, investigations were also carried out on the synthetic methodology for six-membered and nitrogen-containing heterocycles, substituted quinolines under Vilsmeier conditions; when put the same substract in the guanidinium lactate ionic liquids, a series of novel enaminones were synthesized. The contents in this thesis mainly include three parts.(1) An efficient one-pot synthesis of substituted quinolines fromα-arylamino ketones in the presence of PBr3 in DMF has been developed. This general protocol provides a novel and facile access to substituted quinolines by sequential Vilsmeier-Haack reaction, intramolecular cyclization and aromatization reactions ofα-arylamino ketones. PBr3 plays a dual role in the quinoline synthesis: as a key component of the Vilsmeier reagent (PBr3/DMF) and as a reducing reagent.(2) We demonstrated a simple and highly efficient reaction ofα-arylamino ketones to obtain 1,4-diaryl-2-(arylamino)but-2-ene-1,4-diones in excellent yields in mild reaction conditions in guanidinium lactate ionic liquid. The work-up is simple and guanidinium lactate ionic liquid can be at least reused five runs without any catalytic activity loss. The 1,4-diones we got have two aro-acyls which are very important intermediates in organic chemistry. Synthetic transformations using this type of compounds as scaffolds are currently under investigation in our laboratory.(3) A facile and convenient synthesis of substituted imidazo[1,2-a]pyridines has been developed via the reaction of commercially available 2-bromo-1-arylethanones and pyridin-2-amines in the presence of NaHCO3 under mild conditions. With these compounds in hand, we got their substitutes by Vilsmeier-Haack reaction and halogenation in C-3 position. Particularly valuable features of this protocol including mild conditions, simple execution, broad substrate scope, and good yields of products make it an efficient and promising synthetic strategy to expand the type ofimidazo[1,2-a]pyridines.