Design,synthesis and biological activity of novel herbicides targeted ALS(Ⅻ)--Quantitative structure-activity relationships of herbicidal l,2,4-triazolo[l,5-a]pyrimidine-2-sulfonanilides

<正> The herbicidal activities of a series of 1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonanilides containing various substituents on the benzene ring were quantitatively analyzed with physicochemi-cal parameters by using Hansch-Fujita method.Variations in the activity were parabolically related to electronic parameters with the optimum pKavalue being about 6.93.The hydrophobic factor in addition to the electronic property seemed to have important effect on the activity.