Catalyst-free Synthesis Of Pyrido[1,2-a]Pyrimidines Using Water As Solvent

This thesis aims at the studies on the new method for synthesis of pyrido[1,2-α]pyrimidines with2-aminopyridine and dialkyl ethylenedicarboxylates by catalyst free in the presence of air under ambient conditions. Which is divided three parts as follows:Part one:The applications of pyrido[1,2-α]pyrimidinesPyrido[1,2-α]pyrimidines are a well known class of nitrogencontaining heterocycles that find extensive use in the pharmaceutical and agrochemical substances. It is the core structure of the many well know drugs, such as paliperidone for treatment of schizophrenia, risperidone, barmastine as antiallergic agent, pirenperone as ataractic. In addition, many of the compounds containing the core structure of pyrido[1,2-α]pyrimidines has been used in clinical treatment of fields, such as analgesic, anti-inflammatory and anticancer.Part two:Developments of the synthesis of pyrido[1,2-α]pyrimidinesIn view of the attractive medicinal properties of the pyrido[1,2-α]pyrimidine skeleton, simple and efficient methods for the preparation of such compounds are of considerable interest in synthetic organic chemistry. Many of the compounds was developed into commodity. As reported methods for synthesis of these heterocycles in the literature, most of them are starting from2-aminopyridine.Part three:Catalyst-free synthesis of pyrido[1,2-α]pyrimidines using water as solventWe find a kind of efficient, easy, without catalyst green method to synthesis of a series of pyrido[1,2-α]pyrimidines from2-aminopyridine and dialkyl ethylenedicarboxylates, and the corresponding adducts were achieved in moderate to good yields. All products were further characterized by H NMR,C NMR, HRMS.