Microreactor In The Synthesis Of Nitrogen-containing Heterocyclic Compounds, And Styrene Oxide Catalyzed Ring-opening Reaction Studies

Recently, the use of microreactors for chemical industry has drawn a lot of attention. The microreactor is a kind of continuous flow tubular reactor. The typical dimensions of it is much smaller than the traditional reactors. Due to this microstructure and high surface area-to-volume ratio, it has particularly excellent heat and mass transfer characteristic. By introducing such a reaction system into the organic reactions, the temperature of the reaction can be controled precisely. And the reactants can be mixed immediately in accurate proportion, which increase the reaction yield, selectivity and safety.First, the structural characteristics, design and construction, and catalytic modification of the microreactor were reviewed, and examples of its application and development status in organic synthesis were introduced.Then, an appropriate micro-reaction system was designed, and the N-Heterocyclization of arylamines with dihalides has been studied in an aqueous/ethanol medium. A series of N-containing heterocyclic compounds were synthesized in this reaction system. With this method, a high level control of reaction process was achieved easily because of fast mixing and accurate residence time control. Compounds have been synthesized at excellent yields within much shorter reaction time than traditional methods. In addition, the cyclization of ester-substituted aniline was studied to confirm the good prospects in improving the reaction selectivity.The research of quinazolinone derivatives compounds has drawn a lot of attention because of their important medical values. A practical, rapid, and efficient reaction using micro-reactors for the combinatorial synthesis of 2,2-disubstituted quinazolin-4(1H)-one derivatives has been studied, with 2-aminnobenzamide as the raw material, p-toluenesulphonic acid as catalyst, and at an elevated temperature. Compared with traditional methods, this improved synthetic methodology is simple, due to which, the reaction time has been shortened and the yields has been improved. And the process could be applied in industry. Finally, we tried to load the solid phase catalyst into the microreactor to catalyze the ring opening reaction of styrene oxide. Using the coating deposition and direct reaction method, the metal- organic framework HKUST-1 and copper(â…¡) malonate were loaded in the steel pipeline as Lewis acid catalysts for the solid - liquid phase catalytic ring opening reaction. Compared to the traditional methods, the catalytic reaction has achieved superior results in the sealed micro-channels. The reaction time was shorted, and the reuse of this catalyst loading reactor was feasible.