Study On Condensation Reaction Of Aromatic Aldehyde And Aromatic Ketones Under Solvent-free Conditions.

Condensation is one of important reactions in organic synthesis. It play a key role in synthesizing heterocyclic compounds due to their important performance in a variety of disciplines and forming carbon carbon double bond. In recently, the application of Solvent-free method to organic synthesis has been the focus of considerable attention in recent years and becoming an emerging technology that could make industrially important organic syntheses more environmentally eco-friendly than solution reactions. Moreover, the couple Microwave Irradiation with solvent-free offer a new method for organic synthesis. Enhancement of a chemical reaction can manifest itself in several ways including the following: (l)highly accelerated reaction rates for various types of reactions; (2) improved yield in many cases; (3) reduction in side products; (4) simplification and improvement of classical synthetic methods, etc.The destination of this thesis is to study the condensation of fragrant aldehydes and fragrant ketones under solvent-free and Microwave irradiation. It is expected that synthesis of the aimed products under mild condition from commercially available materials and expand the application of microwave irradiation and Solvent-free in organic synthesis.The thesis includes five chapters. Chapter one: The advance of eco-friendly synthesis under microwave irradiation.This part covers the new advance of the environmentally eco-friendly synthesis under microwave irradiation in solvent-free, ionic liquid, water, solid phase, etc. Chapter two A novel method for synthesis of polysubstituted cyclohexanol via phase transfer catalyzed under solvent-free conditions.The application of Solvent-free and phase transfer catalyst to organic synthesis has been attractive in recent years. In this section, we focused on the investigation of the condensation, Michael reaction of different aromatic aldehyde with different aryl substituted ketones under solvent-free and PTC conditions, obtained polysubstitutedcyclohexanol derivatives in mordent yield when using TBAB as the catalyst. In the experiment, we found that the reaction time (3-7min) in solvent-free condition is much shorter than those in solution (16-72h).The reaction is a straight forward metholodology for the synthesis of polysubstitutedcyclohexanol and advantages of the method are the excellent yields, operational simplicity, short reaction time, and avoidance of the use of solvent.Chapter three: Synthesis of 1,5-diketones derivatives under solvent-free conditions at room temperature.1,5-Diketones are extremely important synthetic intermediates in, their own right and are desirable starting materials for preparing many heterocyclic and polyfunctional compounds. This chapter includes the reaction of different fragrant aldehyde with different aryl substituted ketones under solvent-free conditions, and lead to 1,5- diketones. Using these methods, we obtained ten kinds of compounds. The products were characterized by modern spectral data.Chapter four: A rapid synthesis of 2,4,6-triarylpyridines under microwave irradiation and phase transfer catalyst.In this chapter, we firstly used the microwave irradiation and PTC technology to accelerate the conversion of 2,4,6-triarylpyrylium salts with ammonia in solventless condition and one-pot synthesized the 2,4,6-triarylpyridine derivatives. In comparison with literature method, the salient features of the microwave and PTC approach are rapid reaction rates and result in significant energy saving, clean reaction conditions, enhancement in chemical yields, and avoiding the use of organic solvent, which will result in cost saving and minimize safety concerns in the organic laboratory. Finally, the use of solventless reaction conditions results in simple, environmentally friendly workup procedures. This rapid and easy technique coupled with water media may contribute to the dream of Green Technology. In the experiment, taking the conversion of 2,4,6- triphenylpyrylium salt with ammonia as an example, we studied the influence of microwave power, time, p...