3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物的合成及其除草活性的研究

为了进一步研究3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物的除草活性, 以期发现更高活性化合物, 合成了16个未见文献报道的3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物, 其结构均经过¹H NMR, IR和元素分析确证. 生测结果表明, 嘧啶环1-位取代基的变化, 不仅影响化合物的抑制活性与选择性, 可能还改变了化合物的作用方式. 定量的结构与活性关系研究表明, 当作用对象为油菜时, 化合物的活性可能主要与取代基R的摩尔分子折射常数有关; 当作用对象为稗草时, 化合物的活性可能主要与取代基R的电性参数有关. 1-位为氢时, 有利于对油菜生长的抑制; 1-位为甲基时, 有利于对稗草生长的抑制.

Synthesis and Herbicidal Evaluation of 3-Substituted Benzyl-6- (trifluoromethyl)pyrimidine-2,4(1H,3H)-dione Deriva-tives

In order to further study the herbicidal activity of 3-substituted benzyl-6-(trifluoro-methyl)pyrimidine-2,4(1H,3H)-dione derivatives and find new herbicides, sixteen new 3-substituted ben-zyl-6-(trifluoromethyl)pyrimidine-2,4(1H,3H)-dione derivatives were synthesized and confirmed by 1H NMR, IR spectra and elemental analysis. The bioassay results showed that the title compounds herbicidal activity, selectivity and action mode were influenced by the substituent at 1-position for pyrimidine ring. Quantitative structure-activity relationship studies showed that when the test grass was rape, their herbicidal activity was mainly related with substituent molar refractivity (MR); when the test grass was barnyard grass, their herbicidal activity was mainly related with the electronic parameters of the substituents at the para-position of benzene ring. When the substituent at 1-position for pyrimidine ring was hydrogen, the inhibition against rape was improved, while when the substituent at 1-position for pyrimidine ring was methyl group, the inhibition against barnyard grass was improved.