N-(4''''-取代嘧啶-2''''-基)-2-甲氧羰基-5-(取代)苯甲酰胺基苯磺酰脲化合物的合成及除草活性研究

为进一步寻找高效、安全和对环境更加友好的除草剂,以商品化除草剂单嘧磺酯为研究基础,对其结构中的苯环5-位取代基作了结构修饰,合成了26个未见文献报道的新型N-(4'-取代嘧啶-2-基)-2-甲氧羰基-5-苯甲酰胺基苯磺酰脲化合物,通过1H NMR、质谱及元素分析确定了化合物的结构.经油菜平皿法及盆栽法测试了所有化合物的除草活性,结果表明,当苯环5-位取代基为苯甲酰胺时,活性较好,其对双子叶植物的除草活性与商品化的甲嘧磺隆相当.     

N-(4'-取代嘧啶-2'-基)-2-甲氧羰基-5-(取代)苯甲酰胺基苯磺酰脲化合物的合成及除草活性研究

为进一步寻找高效、安全和对环境更加友好的除草剂, 以商品化除草剂单嘧磺酯为研究基础, 对其结构中的苯环5-位取代基作了结构修饰, 合成了26个未见文献报道的新型N-(4'-取代嘧啶-2'-基)-2-甲氧羰基-5-苯甲酰胺基苯磺酰脲化合物, 通过¹H NMR、质谱及元素分析确定了化合物的结构. 经油菜平皿法及盆栽法测试了所有化合物的除草活性, 结果表明, 当苯环5-位取代基为苯甲酰胺时, 活性较好, 其对双子叶植物的除草活性与商品化的甲嘧磺隆相当.     

新型含三唑啉酮的磺酰脲类化合物的合成、晶体结构及除草活性研究

为了进一步寻找高效的磺酰脲类除草剂,以商品化磺酰脲类除草剂为基础,将三唑啉酮杂环引入到分子中,合成了23个未见文献报道的新型磺酰脲化合物,通过1H NMR、高分辨质谱以及X射线单晶衍射确定了其结构.经盆栽法和平皿法测试了所有化合物的除草活性以及部分化合物对油菜的IC50值.结果表明,化合物5h具有优秀的除草活性,其对油菜的IC50值与对照药醚苯磺隆和醚磺隆相近,在3.75 g/ha浓度下对单子叶杂草稗草具有优异的盆栽抑制活性.     

微波及超声波辅助合成新型苯环5位Schiff碱取代苯磺酰脲类化合物及除草活性研究

应用微波及超声波等方法辅助,合成了8个新型Schiff碱取代的磺酰胺,进而合成出了16个新型磺酰脲化合物.经1HNMR,MS及元素分析确证了结构,经油菜平皿法和盆栽法测试了16个磺酰脲化合物的除草活性.结果表明,含有Schiff碱取代基的磺酰脲类化合物对双子叶杂草仍然能保持较好的除草活性.     

2-甲基-6-氯苯基磺酰脲衍生物的合成及生物活性

为探索磺酰脲类化合物的生物活性多样性,以商品化磺酰脲除草剂为基础,设计并合成了12个未见文献报道的2-甲基-6-氯苯基磺酰脲衍生物,通过1H NMR,13C NMR和HRMS确定了其结构.经盆栽法除草测试表明,目标化合物对双子叶靶标油菜和反枝苋具有优异的的除草活性,如5b,5i和5j对油菜和稗草的除草活性与氯磺隆和单嘧磺隆相当.离体抑菌实验表明,在50 mg·L-1剂量下,部分化合物对所测试植物性病菌具有不错的抑菌活性.     

2-甲基-6-硝基苯磺酰脲衍生物的合成及生物活性

设计合成了一系列2-甲基-6-硝基苯磺酰脲衍生物(4a~4p),通过核磁共振氢谱(1H NMR)和高分辨质谱(HRMS)对其结构进行了确认.盆栽法除草测试结果表明,在300 g/ha剂量下,目标化合物具有优异的芽前或芽后除草活性.进一步筛选发现,在75 g/ha剂量下,化合物4b,4g,4h,4l和4p对油菜、反枝苋和稗草具有98%以上的除草活性,与对照药单嘧磺隆(100%)和氯磺隆(≥96.3%)相当.另外,部分化合物对真菌也表现出一定的抑制效果,其中化合物4l对油菜菌核病菌的半最大效应浓度EC50=9.20 mg/L(对照药多菌灵的EC50=5.79 mg/L).     

2-氰基-3-取代丙烯酸(2-乙氧基乙基)酯的合成及除草活性

设计并合成了11个2-氰基-3-取代苯胺基-3-甲硫基丙烯酸(2-乙氧基乙基)酯(2)和11个2-氰基-3-取代苯基脲基丙烯酸(2-乙氧基乙基)酯(5)两类光合作用光系统Ⅱ(PSⅡ)电子传递抑制剂,目标化合物的结构均经1H NMR,13C NMR和质谱分析确证,生物活性测试结果表明:部分化合物2对双子叶杂草表现出良好的选择性和除草活性,化合物5苯环上间位有取代基时有一定的除草活性.     

N-杂环甲基2-(4-杂芳氧基苯氧基)丙酰胺的合成及除草活性

以2-(4-羟基苯氧)丙酸为原料,设计合成了16个新的手性N-杂环甲基2-(4-杂芳氧基苯氧基)丙酰胺化合物,其化学结构经核磁共振、色谱-质谱、红外光谱及元素分析确证.初步生物活性测定结果表明,合成的化合物在2.25×103g/ha剂量时对单子叶杂草马唐(Digitaria sanguinalis)、稗草(Echinochloa crus-galli)及狗尾草(Setaria viridis)等均具有90%以上的活性;进一步活性及作物安全性测试表明,化合物(R)-(+)-N-[(6-氯吡啶-3-基)甲基]-2-[4-(3-氯-5-三氟甲基吡啶-2-基氧基)苯氧基]丙酰胺(2b)的除草活性高于噁唑酰草胺,且对水稻茎叶处理安全,同时对水稻田主要杂草千金子的活性远高于氰氟草酯;化合物的除草活性与立体构型有关,R构型为活性构型.     

(E)-7-(4,6-二甲氧基嘧啶-2-氧基)-2,3-二氢-1H-茚-O-取代-1-酮肟醚类衍生物的合成及除草活性研究

为了发现具有除草活性的新型分子结构,以苯酚为原料,设计合成了13个未见文献报道的新化合物(E)-7-(4,6-二甲氧基嘧啶-2-氧基)-2,3-二氢-1H-茚-O-取代-1-酮肟醚类化合物.化合物的结构通过1H NMR,MS,元素分析进行了表征确证,其中目标物6h进一步通过了单晶衍射.初步生物活性测试结果表明,在试验浓度下部分化合物显示有一定的除草活性,其中化合物6i和6l对测试杂草表现出20%～40%的抑制活性.     

新型含取代苯氧基的2-氰基-3-(2-取代吡啶-5-基)氨基丙烯酸酯类化合物的合成及除草活性

以氰基吡啶氨基丙烯酸酯类化合物为母体,合成了两个系列的含取代苯氧基的2-氰基-3-(2-取代吡啶-5-基)氨基丙烯酸酯化合物,即光系统II(PSII)电子传递抑制剂,以考察不同苯氧基在两个关键位点对其生物活性的影响.生测结果表明:这两个系列化合物均显示出一定的除草活性,其中几种化合物在处理剂量为1.5 kg/ha时,对油菜等阔叶杂草的茎叶处理后的鲜重抑制率达90%以上.从构效关系上,可以初步推测不同苯氧取代基位于氨基吡啶基对位上对除草活性的贡献与其母体氨基吡啶基化合物大致相当,且选择性更好;而在酯基部分对除草活性的贡献不明显.     

Exploiting the Evolutionary Relationship between Malarial Parasites and Plants To Develop New Herbicides

Herbicide resistance is driving a need to develop new herbicides. The evolutionary relationship between apicomplexan parasites, such as those causing malaria, and plants is close enough that many antimalarial drugs are herbicidal and so represent novel scaffolds for herbicide development. Using a compound library from the Medicines for Malaria Venture, the model plant Arabidopsis thaliana, and a physicochemical database of known herbicides, a compound was discovered that showed post‐emergence herbicidal activity equal to commercial herbicides. Using structure–activity analysis, important points for its potency were found. The compound was also tested and found to be active against common crop weeds. Physiological profiling suggested the compound was a photosystem II inhibitor, representing a new scaffold for herbicide development. Overall this approach demonstrates the viability of using antimalarial compounds as lead compounds for the development of much needed new herbicides.     

N-(4-取代嘧啶-2-基)苄基磺酰脲和苯氧基磺酰脲的3D-QSAR研究

采用比较分子力场分析(CoMFA)方法,对两类单取代嘧啶类似物、6个N-(4-取代嘧啶-2-基)-2-甲氧羰基苄基磺酰脲(1a～1f)和14个N-(4-取代嘧啶-2-基)-2-取代苯氧基磺酰脲(2a～2n)进行三维定量构效关系(3D-QSAR)研究.建立了一个较为可靠的预测模型.结果表明,分子中苯环邻位、嘧啶环形成氢键的N原子处以及嘧啶环4位和6位附近负电荷增加;苯环邻位乙氧基的CH₂CH₃附近选择带正电的原子;苯环邻位乙氧基附近空间体积增加,而嘧啶环4位甲氧基稍远处取代基的立体位阻不超过此位置,将有利于提高活性.最后解释了修饰磺酰脲的除草剂仍具有较高活性的原因.     

Discovery of novel 3-{[(5,5-dimethyl-4,5-dihydroisoxazol-3-yl)sulfonyl]methyl}benzo[d]isoxazole analogs as promising very long chain fatty acids inhibitors

Very long chain fatty acids (VLCFAs) are one of the most principal and promising targets for herbicides discovery. In order to explore and find novel VLCFAs inhibitors with higher herbicidal activity and improved crop safety, a variety of new 3-{[(5,5-dimethyl-4,5-dihydroisoxazol-3-yl)sulfonyl]methyl}benzo[d]isoxazole derivatives were reasonably designed and synthesized. The results of greenhouse experiments indicated that several compounds exhibited good herbicidal activity against Digitaria sanguinalis, Echinochloa crus-galli, and Setaria faberii at rates of 150 g ai/ha. Compounds g4 and h1 displayed promising herbicidal activity against D sanguinalis and E crus-galli at rates of 75 g ai/ha, which is better than commercial pyroxasulfone and S-metolachlor. Moreover, compound h1 displayed higher activity against E crus-galli, D sanguinalis, and S faberii than pyroxasulfone and S-metolachlor even at a rate of 37.5 and 18.75 g ai/ha. Furthermore, both of the compounds g4 and h1 were much safer to these tested crops, especially to rice, wheat and rape, at the rate of 150 g ai/ha than pyroxasulfone. Therefore, h1 may act as a new lead structure for novel herbicides discovery.     

苯环5位取代磺酰脲类化合物的水解动力学及三维定量构效关系初步研究

研究了除草活性较好的9个新型苯环5位取代的磺酰脲类化合物(A~I)分别在酸性、中性及碱性水溶液中的水解情况.采用HPLC-MS对水解产物进行分离鉴定,推测了水解产物的结构及水解路径.采用比较分子力场(Co MFA)方法,对化合物的结构与水解半衰期之间的关系进行了三维定量构效关系(3D-QSAR)研究.结果表明,苯环5位取代的苯磺酰脲类化合物的水解遵循一级动力学反应,容易发生酸性条件下的水解,水解反应第一步主要为酸催化下磺酰脲桥的断裂,形成5位取代的苯磺酰胺和氨基杂环.苯环5位取代的苯磺酰胺进一步发生5位酰胺基的水解,最后得到化合物c(6-氨基糖精)和d(糖精).苯环5位经修饰改造后,在相同条件下,其水解速度明显高于改造前的母体化合物单嘧磺酯和甲磺隆.苯环5位为酰胺基取代的化合物的水解速度随酰胺基上烷基碳原子数的增加及烷基体积的增大而降低.经计算所得的Co MFA模型能够对该系列化合物的水解半衰期进行较好的预测.     

Synthesis and Herbicidal Activity of α-Hydroxy Phosphonate Derivatives Containing Pyrimidine Moiety

A series of α‐hydroxy phosphonate derivatives containing pyrimidine moiety were designed and synthesized. Their structures were characterized by IR, ¹H NMR, MS and elemental analysis. The results of preliminary herbicidal activities (in vitro) showed that some of the title compounds 2 exhibited moderate herbicidal activities against dicotyledonous weeds (Brassica campestris L), and most of compounds 2 showed better activity against dicotyledonous weeds than monocotyledonous weeds (Echinochloa crus‐galli). Further bioassays (in vivo) indicated that some of the title compounds 2 possessed good and selective herbicidal activity against amaranth pigweed (A. retroflexus) in both pre‐ and post‐emergence treatments at the dose of 1.5 kg/ha. For exmple, compounds 2a , 2b and 2e exhibited 100% inhibition against A. retroflexus in pre‐emergence treatment, and 91.7%, 98.8% and 99.5% inhibition in post‐emergence treatment at the dose of 1.5 kg/ha, respectively.     

Herbicidal activity of pure compound isolated from rhizosphere inhabiting Aspergillus flavus

In the quest for bioactive natural products of fungal origin, Aspergillus flavus was isolated from rhizosphere of Mentha piperita using Potato Dextrose Agar (PDA) and Czapec Yeast Broth (CYB) nutrient media for metabolites production. In total, three different metabolites were purified using HPLC/LCMS and the structures were established using 500 Varian NMR experiments. Further the isolated metabolites in different concentrations (10, 100, 1000 μg/mL) were tested for herbicidal activity using Completely Randomized design (CRD) against the seeds of Silybum marianum and Avena fatua which are major threats to wheat crop in Pakistan. Among the isolated metabolites, one compound was found active against the test weed species whose activity is reported in the present work. The chemical name of the compound is 2-(1, 4-dihydroxybutan-2-yl)-1, 3-dihydroxy-6, 8-dimethoxyanthracene-9, 10(4aH, 9aH)-dione with mass of 388. Results showed that all seeds germinated in control treatment; however, with the metabolite treated, the growth was retarded to different levels in all parts of the weeds. At a dose of 1000 μg/mL of the pure compound, 100% seeds of S. marianum and 60% seeds of A. fatua were inhibited. Interestingly, the pure compound exhibited less inhibition of 10% towards the seeds of common wheat (Triticum aestivum).     

3-(5′-乙氧基-1,3,4-噻二唑-2′-亚甲氨基)-2-氰基-3-取代-丙烯酸酯类化合物的合成、晶体结构及生物活性

采用氰基丙烯酸酯与5-乙氧基-1,3,4-噻二唑-2-甲氨在乙醇中加热回流的方法合成了一系列3-(5′-乙氧基-1,3,4-噻二唑-2′-亚甲氨基)-2-氰基-3-取代-丙烯酸酯类化合物.目标化合物结构均经1HNMR和元素分析确证.生物活性测试结果表明,部分化合物对双子叶杂草油菜和苋菜显示出较好的除草活性及良好的选择性,用化合物6j在600g/ha剂量下对油菜和苋菜茎叶进行处理,抑制率仍达100%和95.2%,与对照样B相当;氰基丙烯酸酯3位取代基体积对除草活性影响较大,3位为异丙基时活性最高.     

N-[2,4-二取代-5-(3-甲基-2,6-二氧-4-三氟甲基-1,2,3,6-四氢嘧啶-1-基)苯基]酰亚胺类化合物的合成及除草活性

脲嘧啶类化合物具有显著的除草活性. 设计并合成了10个未见文献报道的N-[2,4-二取代-5-(3-甲基-2,6-二氧-4-三氟甲基-1,2,3,6-四氢嘧啶-1-基)苯基]酰亚胺类化合物, 其化学结构经1H NMR, IR, HPLC/MS和元素分析表征. 初步生物活性测定结果表明, 该类化合物具有一定的除草活性, 如9a, 9b, 9c, 9f, 9g和9h在有效成分75 g/hm2剂量下, 茎叶处理对苘麻(Abutilon theophrasti Medic )、刺苋(Amaranthus spinosus)等双子叶杂草的抑制率达90%以上.     

Synthesis and Herbicidal Activities of Sodium Hydrogen 1-(Substituted Phenoxyacetoxy)Alkylphosphonates

Abstract

A series of sodium hydrogen 1-(substituted phenoxyacetoxy) alkylphosphonates was designed and synthesized. The test for herbicidal activity indicated that most of the phosphonates (8) possessed excellent postemergence herbicidal activities against broadleaf weeds. Especially, 8f and 8g showed the best herbicidal activity against rape and amaranth with more than 95% inhibitory rate.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis,crystal structure,and herbicidal activity of pyrimidinyl benzylamine analogues containing a phosphonyl group

A series of pyrimidinyl benzylamine analogues containing a phosphonyl group ( 2 ) was synthesized via the Mannich‐type reactions of 2‐(4,6‐dimethoxypyrimidin‐2‐yloxy)benzoaldehyde 1 , aromatic amines, and dialkyl phosphites or triphenyl phosphite in the presence of Mg(ClO₄)₂. Their structures were characterized by spectroscopic data (infrared, ¹H NMR, ³¹P NMR, and mass spectrometry) and elemental analyses, and compound 2b was further determined by X‐ray diffraction crystallography. The results of preliminary bioassays (in vitro) showed that most of title compounds 2 exhibited higher herbicidal activities against dicotyledonous weeds (Brassica campestris L.) than monocotyledonous weeds (Echinochloa crus‐galli). Further bioassays (in vivo) indicated that some of 2 displayed as good herbicidal activity against amaranth pigweed (Amaranthus retroflexus) as the commercially available herbicide, Bispyribac‐sodium, in both preemergence and postemergence treatments at the dose of 1.5 kg/ha. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:148–155, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20589