Synthesis Of Pyrimidine N-heterocycles From Amidines

As one of the most important chemical compounds in heterocyclic chemistry,N-containing heterocyclic with a large variety,large number,wide distribution and large application value are a kind of structural components of pharmaceuticals,pesticides,materials,dyes and other fine chemical products.In particular,heterocyclic compounds containing pyrimidine ring structure have unique biological activity and pharmacological activity.They are the basic skeletons of many natural products,pharmaceuticals,pesticides and functional materials.Pyrimidines are widely used in the fields of pharmaceutical chemistry and material chemistry,and have been hot topics.Due to the significantly practical implication of pyrimidines,chemists have been devoted to studying the synthesis methods and applications of pyrimidine heterocyclic compounds.A large number of methods for the synthesis of pyrimidines have been reported and have their own advantages and disadvantages.Nevertheless,the development of novel tandem reactions,starting with simple procedures and readily available starting materials to synthesize pyrimidine is of great significance.In this context,the synthesis of 2,4,6-trisubstituted pyrimidines with amidine as substrate was studied.In this paper,the synthesis of 2,4,6-trisubstituted pyrimidine was studied with amidine,alkyne and aldehyde as substrates,t-BuOK as base and DMSO as solvent at 120?.The highlight of this reaction is the "one-pot" reaction in which multiple components are involved in the metal-free catalysis.In addition,the method has the advantages of simple and mild conditions,readily available starting materials,atom-and step-economy,as well as substrate applicability.Mechanistic studies have shown that alkyne and aldehyde form intermediate and react further with amidine under the action of a base,which undergo a cyclization-oxidation process.