The key intermediate iminophosphorane was prepared from 5-aminopyrazole in the presence of triphenylphosphine and hexachloroethane. Eleven 6-alkylamino （ oxy ）-3-methylthio-lH-pyrazolo [ 3,4-d ] pyrimidin-4 （5H）-one derivatives were designed and synthesized via a tandem aza-Wittig reaction. The structures of target compounds were confirmed by 1H NMR, EI-MS, IR spectroscopy and elemental analyses. The results of preliminary bioassay indicate that some compounds possess good herbicida...
