Studies On Novel Synthesis And Properties Of Herbicidal Activity Of Pyrazolo[3,4-d] Pyrimidine Derivatives

Pyrazolopyrimidine and their derivatives,one of the focuses in the research anddevelopment of makeup and agrochemical, medicine have been found to show widespreadbiological activities. Many of them have been used as pesticide, fungicide, phytocide,antitumor, antiphlogosis and curing angiocardiopathy. In this paper, we studied designed, andsynthesized unreported pyrazolopyrimidin using the carbodiimide of ortho-position cyanopyrazole by tandem aza-witting reactions, methanol, ethanol, and various secondary amines asnucleopilic reagent with the silver ion activating cyano respectively. Their herbicidal activitieswere also researched and many of them showed good herbicidal activities. It may besummarized as follows:Forty-four pyrazolopyrimidine and their derivatives in three series were synthesized. Thestructures of all these compounds were confirmed by IR,1H NMR,1C NMR, MS. Thosecompounds are summarized as follows:Ⅰ：5-(substitutedphenyl-)-6-substituted-3-(methylthio)-1-phenyl-1H-pyrazolo[3,4-d]-pyrimidin-4(5H)-imines (14);Ⅱ：N-(substitutedphenyl)-6-substituted-3-(methylthio)-1-phenyl-1H-pyrazolo[3,4-d]-pyrimidin-4-amines (18);Ⅲ：4-imino-3-(methylthio)-1-phenyl-N,N-dipropyl-5-m-tolyl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6-amine (12)The prediminary herbicidal activities of the new compounds mentioned were measured.According to the experiment, some compounds which possessed high herbicidal activities havebeen found.