Synthesis Of The Novel Heterocycle-fused Thiazolopyrimidines

With the in depth study of thiazolopyrimidine compounds,it is shown that these compounds have good biological activity and have good performance in the field of plant protection and medicine.In this paper,the novel thiazolopyrimidine fused heterocyclic compounds were synthesized by Thorpe-Ziegler reaction and Pictet-Spengler reaction,which were divided into five parts.In the first part,the bioactivity and synthesis methods of thiazole,pyrimidine and thiazolopyrimidine derivatives were summarized.The Thorpe-Ziegler reaction and the Pictet-Spengler reaction and their applications in organic synthesis are introduced.In the second part,a mixture of 7-chloromethylthiazolo[3,2-a]pyrimidin-5-one as the starting material and the synthesis of 7-(3-amino-2-benzofuran)-thiazole[3,2-a]pyrimidin-5-one with salicylonitrile by Thorpe-Ziegler,and the synthetic method of the preparation of benzofuroopyridine-thiazolopyrimidine based fused heterocyclic derivatives by Pictet-Spengler reaction was discussed.In the third part,a mixture of 7-chloromethylthiazolo[3,2-a] pyrimidin-5-one as the starting material and the synthesis of 7-(3-amino-thieno[2,3-b]-pyridin-2-yl)-thiazolo[3,2-a]pyrimidin-5-one with 3-cyano-2-pyridinethione by Thorpe-Ziegler,and the synthetic method of the preparation of pyridinethienopyridine-thiazolopyrimidine based fused heterocyclic derivatives by Pictet-Spengler reaction was discussed.In the fourth part,a mixture of 7-chloromethylthiazolo[3,2-a]pyrimidin-5-one as the starting material and the synthesis of 7-(3-amino-benzo[b]thiophen-2-yl)-thiazolo[3,2-a]pyrimidin-5-one with mercapto-salicylonitrile by Thorpe-Ziegler,and the synthetic method of the preparation ofbenz-thiophene-pyridine-thiazolopyrimidine based fused heterocyclic derivatives by Pictet-Spengler reaction was discussed.In the fifth part,N-phenyl-N'-cyanoimino-potassium thiocarbonate was synthesized by the reaction of potassium cyanamide with phenyl isothiocyanate and prepared by condensation of 7-chloromethylthiazolo[3,2-a]pyrimidin-5-one with Thorpe-Ziegler reaction to prepare 7-(3-amino-5-phenyl-aminothiazol-2-yl)-thiazolo[3,2-a]pyrimidin-5-one.Finally,the method of preparation of thiazolo-pyridine-thiazolopyrimidine based fused heterocyclic derivatives by Pictet-Spengler reaction was discussed.The structure of the synthesized product was characterized by elemental analysis,IR and ~1H NMR.