Ma Hong-Ju, Zhang Jian-Hua, Xia Xiang-Dong, Kang Jing, Li Jian-Hong
Department of Plant Protection, College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, China.
Pest Manag Sci. 2015 Aug;71(8):1189-96. doi: 10.1002/ps.3918. Epub 2014 Nov 5.
A series of novel pyrazolylpyrimidine derivatives were designed, synthesised and characterised by IR, (1) H NMR, (13) C NMR, mass spectroscopy and elemental analysis. The herbicidal activities of 30 pyrazolylpyrimidine derivatives were assessed.
Nine compounds caused good herbicidal activity for Pennisetum alopecuroides L. Among them, N-ethyl-6-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]-pyrimidin-4-amine exhibited the strongest inhibitory activity against the root growth of P. alopecuroides, with an IC50 of 1.90 mg L(-1) . 2-Methyl-4-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]-6-(prop-2-yn-1-yloxy)pyrimidine produced the highest inhibition of chlorophyll level in seedlings of P. alopecuroides (IC50 = 3.14 mg L(-1) ).
The structure-activity relationship indicated that the alkynyloxy group at the 6-position on the pyrimidine ring played a very important role for bleaching activities. When the alkynyloxy group was replaced by alkoxy, amino, alkylthio and alkylsulfonyl groups, the bleaching activities of the compounds were diminished. However, the compounds substituted by an amino at the 6-position of the pyrimidine ring exhibited excellent inhibition activities against weed root growth.
设计并合成了一系列新型吡唑基嘧啶衍生物，并通过红外光谱、（1）H核磁共振、（13）C核磁共振、质谱和元素分析对其进行了表征。评估了30种吡唑基嘧啶衍生物的除草活性。
9种化合物对狼尾草具有良好的除草活性。其中，N-乙基-6-[5-甲基-3-（三氟甲基）-1H-吡唑-1-基]-嘧啶-4-胺对狼尾草的根生长表现出最强的抑制活性，IC50为1.90 mg L（-1）。2-甲基-4-[5-甲基-3-（三氟甲基）-1H-吡唑-1-基]-6-（丙-2-炔-1-基氧基）嘧啶对狼尾草幼苗叶绿素水平的抑制作用最强（IC50 = 3.14 mg L（-1））。
构效关系表明，嘧啶环6位上的炔氧基对漂白活性起着非常重要的作用。当炔氧基被烷氧基、氨基、烷硫基和烷基磺酰基取代时，化合物的漂白活性降低。然而，嘧啶环6位被氨基取代的化合物对杂草根生长表现出优异的抑制活性。
