2-(5,7-二甲基-1,2,4-三唑[1,5-a]嘧啶-2-硫代)乙酰胺类化合物的合成及除草活性

以芳胺或取代稠杂环胺、氯乙酰氯和2-巯基-5,7-二甲基-1,2,4-三唑[1,5a-]嘧啶为原料,合成了8个含稠杂环及芳环的三唑并嘧啶类新化合物,结构经1H NMR,M S和IR确证,初步测定了该类化合物在室温下对稗草等3种禾本科杂草和反枝苋等3种阔叶杂草芽前芽后的抑制率,结果表明:有6个化合物在有效剂量75g/hm2下的抑制率超过80%。     

吡啶衍生物研究ⅪⅤ:2-(2-芳氧基吡啶-3-甲酰氧基)丙酸酯的合成及除草活性

以2-氯烟酸和酚类化合物为原料,通过醚化、酯化等反应合成了24个2-(2-芳氧基吡啶-3-甲酰氧基)丙酸酯类化合物,其结构均通过核磁共振氢谱和质谱分析确证.初步除草活性测定结果表明,在100 mg/L剂量下,部分目标化合物对马唐Digitaria adscendens和苘麻Abutilon theophrasti的抑制率可达100%.     

吡啶衍生物研究 Ⅹ Ⅳ:2-(2-芳氧基吡啶-3-甲酰氧基)丙酸酯的合成及除草活性

以2-氯烟酸和酚类化合物为原料,通过醚化、酯化等反应合成了24个2-(2-芳氧基吡啶-3-甲酰氧基)丙酸酯类化合物,其结构均通过核磁共振氢谱和质谱分析确证。初步除草活性测定结果表明,在100 mg/L剂量下,部分目标化合物对马唐Digitaria adscendens和苘麻Abutilon theophrasti的抑制率可达100％。     

N-[4-叔丁基-6-芳基-5-(1,2,4-三唑-1-基)-1,3-噻嗪-2-基]酰胺类化合物的合成及抑菌活性

以α-三唑基频那酮为起始原料,经缩合、环化和酰胺化反应合成了15个未见文献报道的化合物,其结构均经核磁共振氢谱、红外光谱和质谱确认。初步抑菌活性测试结果表明,在50 mg/L下,目标化合物对供试植物病原菌均有不同程度的抑制作用,其中化合物3a-3、3a-4、3a-5、3b-2和3b-3对番茄灰霉病菌Botrytis cinerea的抑制率达80%以上,3a-4和3a-5对棉花枯萎病菌Fusarium oxysporum vasinfectum的抑制率分别达78.6%和82.4%。     

1-取代苯胺基- 4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮的合成及其生物活性

为寻找高活性的烯基三唑类杀菌剂,利用1-二甲氨基-4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮与取代苯胺进行亲核取代反应,合成了一系列新型1-取代苯胺基-4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮化合物,其结构经元素分析、核磁共振氢谱确认。由1H NMR分析结果推测该类化合物E式构型为优势产物。初步生物活性测试结果表明,化合物 1n (取代基R=3-OCH3)在50 μg/mL浓度下对葡萄白腐菌Coniothyrium diplodiella、黄瓜黑星菌Cladosporium cucumerinum等的抑制率均达到100%;在10 μg/mL浓度下对促进黄瓜子叶生根的活性达到155.2%。     

吡啶衍生物研究Ⅷ:2-烷氨基-5-(2-芳氧吡啶-3-基)-1,3,4-噻二唑类衍生物的合成与及生物活性

以2-取代苯氧基烟酰肼为原料,与异硫氰酸酯反应合成了14个结构新颖的2-烷氨基-5-(2-芳氧吡啶-3-基)-1,3,4-噻二唑类化合物,其结构通过 1H NMR、IR和元素分析表征。初步生物活性测试结果表明,化合物 4j 在50 mg/L下对黄瓜枯萎病菌Cladosporium cucumerium的抑制率可达70％。     

吡啶衍生物研究(X):2-仲丁氨基-5-(2-芳氧吡啶 -4-基)-1,3,4-噻二唑的合成及除草活性

为了研究2-仲丁氨基-5-(2-氯吡啶-4-基)-1,3,4-噻二唑(BCPT)的结构-活性关系和开发活性更高的新型除草剂,以BCPT为先导化合物,依据活性亚结构连接法,在吡啶环2-位上引入二芳醚类除草剂的典型结构单元——芳醚,设计并合成了一系列新的芳氧吡啶噻二唑类化合物,其结构经元素分析和1H NMR确证。初步除草活性测定结果表明,在500 mg/L剂量下,所有化合物的除草活性(抑制率0~45%)远低于先导化合物(抑制率72％~87%),说明吡啶环2-位上的氯原子可能对维持该类化合物的除草活性是必需的。     

6-氟-2-嘧啶氧基-N-取代苯基苄胺类化合物的合成及其除草活性

从起始原料引入氟原子,分别经亚胺化、硼氢化钠还原、嘧啶氧化,及嘧啶氧化、溴化、胺化两条路线合成了28个新型的6-氟-2-嘧啶氧基-N-取代苯基苄胺类化合物;同时测试了该类化合物在温室中对稗草Echinochloa crusgalli等3种禾本科杂草和反枝苋Amaranthus retroflexus等3种阔叶杂草芽前、芽后的抑制率,结果表明,有12种目标化合物在有效剂量75 g/hm2下其抑制率超过80%。     

3-芳氧基-6-氯(或氟)哒嗪类化合物的合成及除草活性研究

从3,6-二氯哒嗪( Ⅰ) 出发,通过氟代得到3,6-二氟哒嗪( Ⅱ )。将 Ⅰ,Ⅱ 分别与取代苯酚缩合,得到了18个3-芳氧基-6-氯哒嗪( Ⅲ )和12个3-芳氧基-6-氟哒嗪( Ⅳ )。所有目标化合物( Ⅲ,Ⅳ )的结构都经过 1H NMR和元素分析确证,部分化合物经IR确证。初步的生物测定结果表明,目标化合物具有不同程度的除草活性,其中化合物 Ⅲ3、Ⅲ8和Ⅳ2 在100 μg/mL的浓度下对稗草Echinochtoa crus-galli的抑制率分别达到95.7%、96.1%和91.2%。     

氨基甲酸-2-氯吡啶-5-甲酯化合物的合成与抑菌活性

以芳香硝基化合物、2-氯-5-吡啶甲醇和一氧化碳为原料,在Pd-Fe/Ti O2催化下进行羰基化反应,合成了11个新型氨基甲酸-2-氯吡啶-5-甲酯化合物,其结构经1H NM R和M S表征。初步抑菌活性测定结果表明:在50 mg/L下,大多数目标化合物对4种供试病原菌具有一定的抑制活性,其中化合物3f(4-甲氧基苯基氨基甲酸-2-氯吡啶-5-甲酯、3h(2,4-二氯苯基氨基甲酸-2-氯吡啶-5-甲酯)和3j(3,4-二氯苯基氨基甲酸-2-氯吡啶-5-甲酯)对小麦赤霉病菌Gibberella zeae的抑制率达77.3%以上,3f对苹果轮纹病菌Physalospora piricola的抑制率达82.5%,与对照药多菌灵接近;所有化合物在50 mg/L下对番茄灰霉病菌Botrytis cinerea的抑制活性均优于对照药多菌灵。     

New herbicidal derivatives of 1,2,4-triazolo [1,5-a] pyrimidine

Two new structural classes of herbicide have been discovered which are based on the 1,2,4-triazolo[1,5-a]pyrimidine ring system. These compounds are related to the known herbicidal sulfonylureas and imidazolinones and other studies have shown that they have a similar mode of action, involving the inhibition of branched-chain amino acid biosynthesis, the site of action being the enzyme acetolactate synthase. The design, synthesis and structure- activity relationships of these new classes of compounds are described.     

Pyrimidinyl-substituted amides and thioureas: syntheses, crystal structure and herbicidal activities

BACKGROUND: The high herbicidal activities of [1,2,4]triazolo[1,5-c]pyrimidine and 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivatives suggested the development of new fused heterocyclic compounds for application as herbicides. RESULTS: Three series of pyrimidinyl-substituted thioureas (4) and amides (5, 6) were synthesized, and the typical crystal structure of a 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivative (5a) was determined by X-ray diffraction. All the compounds were tested for herbicidal activity against selected weeds. CONCLUSION: The series of fused heterocyclic amides 5a to 5d exhibited high herbicidal activities both against monocotyledonous weeds (Echinochloa crus-galli L., Sorghum bicolor (L.) M?nch., Digitaria sanguinalis (L.) Scop) and against dicotyledonous weeds (Amaranthus retroflexus L. and Brassica campestris L.) in pre-emergence treatments. In particular, compound 5b at low concentration still showed high inhibitory activity against A. retroflexus in pre-emergence treatment. Different substituents at the meta positions of the pyrimidine ring were found to affect the herbicidal activity.     

New heterocyclic herbicidal sulphonamides

The sulphonylurea structures and their relationships with the 1,2,4-triazolo[1,5-a]pyrimidinesulphonamides are first discussed. Three novel examples of heterocyclic sulphonamides, pyrazolo[1,5-a]pyrimidine-2-sulphonamides, thiazolo[3,2-b][1,2,4]triazole-2-sulphonamides and 1,2,4-triazole-3-sulphonamides are highlighted and their synthesis, biological activity and soil behaviour are described.     

取代苯氧基三唑并嘧啶类化合物的合成及除草活性研究

以砜基取代的嘧啶为关键中间体,设计合成了17个新型取代苯氧基1,2,4-三唑并 嘧啶类衍生物,通过元素分析、MS和1H NMR对所合成的化合物进行了结构表征。初步生物活性测定结果表明,100 mg/L浓度下部分化合物对6种测试靶标均表现出较好的抑制活性,盆栽复筛试验显示在150 g/hm2剂量下,5个化合物表现出较好的除草活性和持效性。     

Mechanism of action of the 1,2,4-triazolo[1,5-a] pyrimidines

The substituted 1,2,4-triazolo[1,5-a]pyrimidines are a new class of highly active herbicides. Protection of Arabidopsis thaliana seedlings from triazolopyrimidine-induced injury by the branched-chain amino acids was observed. Acetolactate synthase (EC 4.1.3.18) was isolated and found to be quite sensitive to inhibition. I₅₀ values for inhibition of the enzyme from a number of plant sources show little variation and no correlation to whole-plant response, suggesting uptake, translocation and metabolism play key roles in modulating herbicidal activity. Further studies indicate that these chemicals are slow, tight-binding inhibitors that are readily dissociated by gel filtration. Some correlations between in-vitro activity and in-vivo activity were observed for ortho-substituted analogs on selected broadleaf species.     

Uptake and metabolism as mechanisms of selective herbicidal activity of the 1,2,4-triazolo[1,5-a] pyrimidines

In order to identify the factors providing the triazolopyrimidines with a wide range of selectivity amongst agriculturally important plant species, studies were made on the uptake and metabolism of a representative compound, N-(2,6-dichlorophenyl)-5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine- 2-sulfonamide. This compound is much more phytotoxic to dicots than to monocots. Experiments showed that variations in leaf morphologies and geometries relative to spray applications resulted in different herbicide dosages applied to plant species used in selectivity evaluations. However, this parameter did not have a statistically significant correlation to herbicide selectivity measurements. Characterization of the metabolic pathways showed that the major herbicide metabolites involved methyl hydroxylation or hydroxylation of the aniline ring followed by glucose conjugation. Since these metabolites were not exclusive to either monocots or dicots, herbicide selectivity does not appear dependent on the pathway of metabolism. Studies on the kinetics of metabolism suggest instead that metabolic rate was important. Monocots metabolized the herbicide rapidly and generally were tolerant while the opposite was true of dicots.     

三唑并嘧啶磺酰胺类除草剂的研究概况

三唑并嘧啶磺酰胺类除草剂是将磺酰脲类除草剂通过脲桥的结构改造和修饰而得,它既保持了磺酰脲类除草剂的超高效性,又克服了一些磺酰脲类除草剂品种在土壤中残留期较长、易对后茬作物造成伤害等缺点。本文综述了三唑并嘧啶磺酰胺类除草剂的结构、主要品种、作用机理、应用研究和发展前景。     

7Th international congress of pesticide chemistry

A series of 2-(1,3-dimethyl-4-substituted-5-pyrazolyl)sulfonylimino-5,7-disubstituted-2H-1,2,4-thiadiazolo[2,3-a]pyrimidines was synthesized and tested for herbicidal effects. The compounds showed potent activity and improved selectivity to rice when compared with analogous sulfonylurea derivatives.     

2H-1,2,4-噻二唑并[2,3-a]嘧啶衍生物的合成及除草活性研究(Ⅱ)

取代苯氧乙酸及其衍生物、酰基硫脲[1]和2H-1,2,4-噻二唑并嘧啶类化合物[2]都是具有很好生物活性的母体结构。前文[3]曾报道了2H-1,2,4-噻二唑并[2,3-a]嘧啶的苯甲酰亚胺衍生物的合成及除草活性测定。为了寻找高效、高选择性的新型除草剂,本文以2-氯苯氧乙酰异硫氰酸酯1为创制源合成了未见文献报道的4个2和4个3。化合物2和3的结构经元素分析、IR和1HNMR确证。合成路线如下:OCH2CNCSOCl NNH2NXZY丆lOCH2CNHOCSNHNNXZY　　　　　　　1　　　　　　　　　　　　　　　　　　　　　　　2Br2NNYZXNSOCH2CNOCl32/3abcdXCH…