Forty-six novel 1, 2, 4-triazolo[1, 5-a] pyrimidine derivatives are designed and synthesized based on the staring material 2-merpto-5, 7-dimethly-1, 2, 4-triazolo[1, 5-a] pyrimidine. All compounds synthesized are identified by 1H NMR, MS and elemental analyses. Preliminary bioassay indicates that some compounds display herbicidal...