title: Novel protoporphyrinogen oxidase inhibitors: 3H-pyrazolo[3,4-d][1,2,3]triazin-4-one derivatives.
abstract: A series of 3 H-pyrazolo[3,4-d][1,2,3]triazin-4-one derivatives were synthesized as candidate herbicides by diazotization of different 5(3)-amino- N-phenyl-1 H-pyrazole-4-carboxamide derivatives prepared by the reaction of substituted 5(3)-amino-pyrazole-4-carbonyl chloride with a substituted aniline. Their structures were identified by (1)H NMR and elemental analyses. The isomers D and E were isolated, and their structures were identified by two-dimensional NMR analyses (heteronuclear single quantum coherence and heteronuclear multiple-bond correlation) and single-crystal X-ray diffraction analysis. The bioassay results showed that some of the title compounds exhibited both excellent herbicidal activity at a dose of 93.75 g/ha and strong inhibition against protoporphyrinogen oxidase activity in vitro. The structure-activity relationship showed that D16 possessed the highest activities both in vivo and in vitro when the N-substituted group of the pyrazole ring was allyl and the N-substituted group of benzooxazinone was propargyl.
authors.affiliation: State Key Laboratory of Elemento-organic Chemistry, Institute of Elemento-organic Chemistry, Nankai University, Tianjin 300071, People's Republic of China.
authors.forename: Hua-bin
authors.initials: HB
authors.lastname: Li
authors.forename: You-quan
authors.initials: YQ
authors.lastname: Zhu
authors.forename: Xiao-wei
authors.initials: XW
authors.lastname: Song
authors.forename: Fang-zhong
authors.initials: FZ
authors.lastname: Hu
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Yong-hong
authors.initials: YH
authors.lastname: Li
authors.forename: Zi-xia
authors.initials: ZX
authors.lastname: Niu
authors.forename: Pei
authors.initials: P
authors.lastname: Liu
authors.forename: Zhi-hong
authors.initials: ZH
authors.lastname: Wang
authors.forename: Hai-bin
authors.initials: HB
authors.lastname: Song
authors.forename: Xiao-mao
authors.initials: XM
authors.lastname: Zou
authors.forename: Hua-zheng
authors.initials: HZ
authors.lastname: Yang
mesh_terms: D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry*; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry*; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D010940:Plant Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006109:Poaceae / Q000187:drug effects / Q000201:enzymology; D050768:Protoporphyrinogen Oxidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014227:Triazines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D010940:Plant Proteins; D011720:Pyrazoles; D014227:Triazines; D050768:Protoporphyrinogen Oxidase