Study On The Synthesis Of Nitrogen-Containing Heterocyclic Compounds Via Multicomponent Reactions

In this thesis, a number of series of nitrogen-containing heterocyclic compoundsare synthesized via Multicomponent Coulpling Reactions (MCR). The remarkableadvantages of all the mentioned reactions are easy source of materials, easy work-up,mild reaction conditions, short reaction time, high yields and atomic economy.The use and significance of the nitrogen-containing heterocyclic compounds andthe recent progresses of Multicomponent Coulpling Reactions (MCR) at home andabroad in the field of synthesis of the nitrogen-containing heterocyclic compounds wereintroduced in the first chapter.In the second chapter, synthesis of pyrimidine derivatives was reported viaMulticomponent Coulpling Reactions (MCRs). Firstly, one-pot reaction for thesynthesis of4-aryl-5-cyano-1,6-dihydro-2-thiouracils via three-component fromaromatic aldehydes, ethyl2-cyanoacetate and S-benzylisothiourea hydrochloride isdescribed. Meanwhile, the appropriate solvent, catalyst, temperature, and reaction timehad been discussed. Secendly, we studied the multicomponent reaction of series of newpyrimidine derivatives with aromatic aldehydes, molononitrile and guanidine(nitroguandine, cyanoguanidine, S-methyliosthiouronium sulfate, S-benzylisothioureahydrochloride), which greatly expanded the scope of such compounds. Similarly,we also explored the appropriate solvent, catalyst, temperature, and reaction time.In the third chapter, the successful and efficient synthesis of a series of2-amino-benzo[h]quinazoline derivatives via three-component from aromatic aldehydes,1-tetralone and cyanoguanidine (nitroguandine) were reported, and the appropriatesolvent, catalyst, temperature, and reaction time had been studied. This method has theadvantages of a short reaction time, convenient post-processing, high yields and goodadaptability which provide a more efficient synthesis of these compounds.In the forth by catalysis of the organic base triethylamine to promote reactionsolventethanol to participate in the reaction, a series of2-amino-3,5-dicyano-4-arylpyridine derivatives were synthesized from aromatic aldehydes and malononitrile,and the appropriate catalyst, temperature, and reaction time had been studied. Thismethod of the reaction has the advantages of reaction materials easy to gain, a shortreaction time, convenient post-processing, high yields and good adaptability whichextend the scope of the application of such reactions.All of the compounds obtained by the above mentioned reactions were characterized by IR,1H NMR, HRMS. The possible reaction mechanisms were putforward.In the fifth chapter, the main laboratory apparatus and chemical reagent that usedduring the experiment had been summarized. And there listed the detailed operatingsteps.In the sixth chapter, the experimental results of the paper on the multi-componentsynthesis of nitrogen-containing heterocyclic compounds had been summarized.