关键词: >除草活性, 四嗪酮, 定量构效关系

A series of 4-ethoxycarbonyl-1,7-dihydro-1-(substituted phenyl)-5-(un)substituted pyrazolo- [5,1-d][1,2,3,5]tetrazin-7-one derivatives were designed and synthesized. Their structures were confirmed by ¹H NMR, IR spectra and elemental analysis. The bioassay results showed that these compounds exhibited better herbicidal activity. Quantitative structure-activity relationship studies showed that their herbicidal activity was correlated with the substituent molar refractivity (MR), steric or hydrophobic physicochemical parameters, where the correlation coefficients were larger than 0.8. The herbi-cidal activity against Brassica campestris was mainly effected by the MR for R¹ and the hydrophobic parameter (π) for R². When MR was about 1.452, the compound showed the highest herbicidal activity. The herbicidal activity against E. crus-galli was mainly related with Taft (Es) for the ortho-R² and the hydrophobic parameter (π) for the ortho- and meta-R².

Key words: tetrazinone, quantitative structure-activity relationship (QSAR), herbicidal activity