Studies On Synthesis And Properties Of Thienopyrimidine And Pyridopyrimidine Derivatives

Thieno-pyrimidines are heterocyclic compounds along with widespread biological and medical activities, such as, some of them have been used as fungicide, herbicide pesticide and medicine. The scientific and practical demands for such compounds are increasing. Pyrimidines are a kind of versatile intermediates in organic synthesis. It can be widely used in forming aromatic and heterocyclic compounds. Therefore, the combination of Pyrimidines and thiophene or pyridine is a good way for the synthesis of Thieno-pyrimidines and pyrido-pyrimidines and their biological activities were also researched.In this dissertation, about three kinds containing thirty-eight unreported compounds were synthesized and confirmed by elemental analysis, 1H NMR,13C NMR,MS,IR,ICP. The general kinds of these compounds are as following:I. 2-S-Alkyl -3- propyl-6-ethyl-Thieno[2, 3-d]pyrimidin-4-oneII. 3-propyl-6-ethyl-Thieno[2, 3-d]pyrimidin-4-one-2-S-acetyl hydrazonesIII. 2- S-Alkyl-5-alkly-6- pyrido[2, 3-d]pyrimidinesIn this paper, we studied the synthesis of novel Thieno[2, 3-d]pyrimidines that has the advantage of easily accessible starting material, mild condition and good yields. The condition for cyclization was researched. Some compounds have been found to show good herbicidal activities.A simple and efficient procedure for synthesis of 2-S-Alkyl-5-alkly-pyrido[2, 3-d]pyrimidines is studied. One-step cyclocondensation takes place between easily accessible starting material (aminopyrimidines), agents (ethyl acetoacetate), catalyst (tin tetrachloride). The biological activities were studied. The results show good herbicidal activities.