The Study Of Constructing Pyrazolo[1,5-c]Quinazoline Derivatives Via 1,3-dipolar Cycloaddition

N-Fused heterocycles are kinds of compounds which are widely used in medicine and pesticide, at the same time, they’re also existed in many natural products. It has attracted more and more researchers’ attention on the study of their synthetic methods and biological activity.On all of the N-Fused heterocycles, pyrazolo[1,5-c]quinazoline derivatives have been widely used in the medicine, they can be used as Gly/NMDA receptor and excitatory amino acid antagonists, potent phosphodiesterase 10 A and potential vaccinia virus inhibitors. To date, there have been many methods frequently used for synthesizing pyrazolo[1,5-c]quinazoline derivatives. While these synthetic methods are generally efficient, they usually suffer from many difficulties, such as harsh reaction conditions, multistep processes, the starting materials are difficult to obtain and so on. Therefore, nowadays we must solve the problem to find some simple and efficient method for synthesizing pyrazolo[1,5-c]quinazoline compounds.We utilized the quinazoline azomethine imines which synthesized by our research group reacted with unsaturated compounds under simple conditions. This reactions were 1,3-dipolar cycloaddition reaction and they can produce the pyrazolo[1,5-c]quinazoline derivatives in one step.This paper mainly includes the following two parts of research content:（1）. This paper described that quinazoline azomethine imines reacted with substituted alkenes if and only if the reaction used the CuCO₃?Cu（OH）₂ as the catalyst and the temperature was up to 70 °C, thus it could produced a series of pyrazolo[1,5-c]quinazoline derivatives smoothly, and it can be selectively substituted on the 1- or 2- addition of pyrazolone ring.（2）. This paper described glycosylation of pyrazolo[1,5-c]quinazoline derivatives. And the reaction condition was relatively simple, it only needed Ag₂ O as the catalyst, DBU as the base, quinazoline azomethine imines can be reacted with sugar terminal alkynes under N₂ atmosphere and 70 °C. Nowadays, glycosylation of heterocyclic compounds are an important topic, they can show a certain role in the pathology. So it has important research significance of this method to constructing glycosyl substituted pyrazolo[1,5-c]quinazoline compounds.This paper described synthesizing pyrazolo[1,5-c]quinazoline derivatives under simple conditions, and the operation of these reactions were simple, the starting materials were cheap and easy to obtain, and it’s easy to separate and purify products. From a viewpoint of the organic synthesis, this work provides a realistic synthesis method to build pyrazolo[1,5-c]quinazoline derivatives.