Four-Component One-Pot Synthesis Of Polyhydroquinolines In PEG-400-Water System

At present, the green organic synthetic chemistry, which is developing environmentally friendly methods in organic synthesis, has attracted more and more attention. Poly(ethylene glycol) (PEG) has many applications, not only in chemistry but also in other diverse disciplines as well. PEG has become very popular in organic synthesis since they are nonvolatile, recyclable, stable to acid, base, and high temperature, and available in high quantities at low prices. Furthermore, their well-known low toxicity makes them greener versions of conventional halogenated solvents.In the field of green chemistry, the ideal synthesis should be using environmentally friendly reagents, and the yield of the products will get to 100% using a few steps. The traditional ideal of organic synthesis reaction is a reaction of raw materials react with other raw materials to form products, while in multi-component reactions, three or more reactants are mixed in a single reaction flask to generate products incorporating most of the atoms contained in the starting material (not including the generation of inorganic and organic small molecules), each intermediate product is the raw materials of next step reaction, and the final product's structure contain all the pieces of the synthesis of the starting material. The synthesis of complex organic compounds, if use the method of traditional synthesis, to multi reaction step and the complex treatment of sludge. In MCR, several chemical bonds can be formed in one step without the need of isolating the intermediates, which reduce the separation operation, improving the efficiency of the reaction, and having clear advantages compared to the traditional methods.From statement above, according to advanced reading many past literatures, firstly, summarizes the PEG as a solvent, reaction medium and its application. Secondly, the progress of polyhydroquinolines derivatives in synthesis and application are summarized, then according to a lot of literature and under experiment, selected the high atom economy, low environmental impact, and mild reaction condition method for synthesis of polyhydroquinolines.This dissertation is classified into two chapters:Chapter 1 The application of PEG in the Synthesis of Heterocycles.In this chapter we reviewed the development and application of PEG in the synthesis of heterocyclic compounds in recent years in detail.Chapter 2 Four-Component One-Pot Synthesis of Polyhydroquinolines in PEG-400-Water System.An efcient one-pot synthesis of polyhydroquinolines is achieved from aldehydes, 1,3-cyolohexanedione, ethyl acetoacetate, and ammonium acetate, in which a four-component reaction is operated in PEG-400-water system. A series of polyhydroquinolines compounds are characterized by IR NMR spectroscopy and MS, the new compounds are also characterized by elemental analys. The reaction here has the following advantages: easy manipulation, short reaction time, environmentally-benign and high yield.