Quinoline compounds were synthesized by extraction and catalytic chemical methods from coal tar, respectively. However, the traditional Skraup method and Friedlander method use inorganic acids or alkalis as catalysts, which require high equipment, especially high environmental pressure; the quinoline prepared by Baylis-Hillman synthesis is rarely used in organic synthesis, mainly because The requirements are strict, and the separation and purification of the products are not convenient. It is only suitable for the preparation of special quinoline derivatives; the transition metal catalytic synthesis technology avoids the use of organic acids, but the transition metal complex catalyst still has a catalyst. A series of shortcomings such as separation and recovery difficulties; but combined with microwave or super sound waves, the reaction speed is greatly accelerated, and the yield is also greatly improved, is an emerging method of synthesizing quinoline.
