The Research On Knoevengal Condensation Catlyzed By The Hydrobromic Acid

Since Emil Knoevenagel, a chemist from Germany, proposed Condensation in 1890s, the related research has been demonstrating the tendency of complexity and variation. The selection of catalyst, asymmetric synthesis, and domino reaction has become the focus regarding this area.Meanwhile, as the development of organic chemistry is increasingly more concerned with green and economical aspect, how to utilize non-toxic and environmentally friendly catalyst to improve catalytic reactions is a challenging subject for scholars to study. The hydrobromic acid selected in this dissertation is a kind of cheap, green and highly reactive catalyst.This dissertation discusses the research on Knoevenagel Condensation catalyzed by the hydrobromic acid. The procedures were carried out as follows:(1)The selection of catalyst, solvent, and temperature optimized the best reaction conditions.(2)The special catalytic reaction of hydrobromic acid was studied through its comparison and contrast with that of other acid.(3)Several Knoevenagel condensation products were produced by changing methylation compounds and types of aldehyde under the above optimized reaction conditions.The advantages of experiment design and synthesis are presented in the following analysis.(1)Effectively green catalytic system: the hydrobromic acid that separated easily from the reaction system proceeds effective and not-toxic catalytic reaction without polluting the environment.(2)Raw materials available and low cost: the dosage of hyrobromic acid as catalyst and its cost tend to be low.(3)High selectivity, mild condition,high yield.