The Ring Formation Mechanism in Cyclization of Berberine

Berberine hydrochloride is a natural alkaloid with significant antitumor activities against many types of cancer cells, can be synthesized by cyclic reaction with hydrochloride condensate and glyoxal as raw materials and copper chloride as catalyst. In this study, the transition and energy change for the each reaction step was calculated by the density functional theory program Dmol3 in Materials Studio 2017. and the results testified that there are two ring formation in the cycliztion process, and according to the result we proposed the mechanism of this cyclization reaction. We also use infrared and ultraviolet spectroscopy to monitor the reaction process in real time and prove the ring formation process. The reaction mechanism was firstly proposed at the basic results of above.