The synthesis of pyrroles with insecticidal activity

The 2-aryl-4-bromo-5-trifluoromethylpyrrole-3-carbonitriles represent a new class of insect control agents. The high insectidical activity observed in this series prompted us to investigate the preparation of regioisomeric arylhalotrifluoromethylpyrrole carbonitriles. The synthesis and biological activity of eight of the twelve possible regioisomers are described and discussed.     

纳米银的绿色合成、杀虫活性和作用机制研究进展

纳米银 (AgNPs) 因具有独特性质已广泛应用于多个领域。由于化学合成纳米银的流程繁琐、高能耗及使用的溶剂毒性强、污染严重等,纳米银的绿色合成研究备受关注。纳米银的绿色合成是指以真菌、细菌培养上清液及植物提取液作为还原剂或稳定剂,将硝酸银中Ag+还原为纳米级别的单质银,具有稳定性高、低毒、绿色环保等优点。一些研究者在绿色合成纳米材料的基础上,研究了通过生物源合成的纳米银用于害虫防治的效果,以探索纳米材料替代传统化学杀虫剂的可能性。本文综述了近年来国内外研究者利用不同生物材料合成纳米银的情况,报告了生物源合成的纳米银对媒介害虫和农业害虫的毒杀效果与作用机制研究进展,简单介绍了生物源合成的纳米银对生物体和环境的暴露风险,并对其研究的机遇和挑战进行展望。     

含吡唑-4-甲酰胺的嗜球果伞素类化合物的设计、合成及杀虫活性

为了发现新的农用高活性化合物,将具有杀螨活性的嗜球果伞素类化合物与具有杀菌活性的吡唑酰胺类化合物的活性亚结构进行拼接,设计并合成了16个新化合物,通过核磁共振氢谱、碳谱及高分辨质谱等手段表征了其结构。生物活性测试结果表明,目标化合物虽然没有预期的杀螨和杀菌活性,但是表现出了良好的杀虫活性,其中8个化合物在500 mg/L下对黏虫Mythimna separata的杀虫活性为100%。     

Insecticidal activity of certain benzodioxolyl carbamates

A series of benzodioxolyl carbamates has been prepared and evaluated in the laboratory for insecticidal activity against a range of ten species. The results indicated that this was optimal with the 4-benzodioxolyl carbamates with a 2,2-dialkyl substitution. The most promising of these on the basis of cost-effectiveness was 2,2-dimethyl-1,3-benzodioxol-4-yl methylcarbamate, bendiocarb, which is being developed commercially for the control of household pests.     

二氢吡唑邻甲酰氨基苯甲酰胺衍生物的合成及杀虫活性

以邻氨基苯甲酸和4,5-二氢吡唑-5-甲酸为原料,制备得到苯并噁嗪酮,所得产物与取代胺作用制得8个结构新颖的二氢吡唑邻甲酰胺基苯甲酰胺类化合物,其结构用核磁共振氢谱和质谱进行了表征。生物活性试验结果表明,在500 mg/L质量浓度下,部分化合物对小菜蛾Plutella xylostella、苜蓿蚜Aphis medicaginis和稻飞虱Nilaparvata lugens的致死率达100%。     

Synthesis and insecticidal activity of nitroguanidine derivatives

Nitroguanidine derivatives with thiazol-5-ylmethyl moieties were prepared and their insecticidal activities against homopterous pests were tested. New synthetic routes for 2-chloro-5-chloromethylthiazole from 2,3-dichloro-1-propene and for substituted nitroguanidines from S-methyl-N-nitroisothiourea were established. Biological evaluation led to a novel insecticide (E)-1-(2-chlorothiazol-5-ylmethyl)-3-methyl-2-nitroguani dine (TI-435) which has a broad activity spectrum and is under development. ©1999 Society of Chemical Industry     

嘧啶酮类衍生物的合成及杀虫活性

为了创制高效广谱的绿色杀虫剂,以(E)-4,5-二氢-6-甲基-4-(3-吡啶亚甲基氨基)-1,2,4-三嗪-3(2H)-酮(吡蚜酮)为先导,用带有不同电荷密度的五元、六元取代苯环或杂环取代其结构中的吡啶环部分,合成了10个全新的嘧啶酮类衍生物,特别对其中所包含的三嗪环和二氢喹唑啉酮合成部分进行了重点研究。所有目标化合物的结构均经过核磁共振氢谱、高分辨质谱及红外光谱的确认。初步杀虫活性测试结果表明,目标化合物对蚜虫Aphis craccivora未表现出明显的杀虫活性,初步暗示了先导化合物吡蚜酮结构中所含的吡啶环部分可能对其杀虫活性起了重要作用。     

含三氟甲基异噁唑啉类化合物的合成及杀虫活性

以取代α-三氟甲基苯乙烯和取代的肉桂醛肟为原料,经过1,3-偶极环加成反应,合成了16个未见文献报道的含三氟甲基异噁唑啉结构的目标化合物,其结构经1H NMR和LC-MS确认。初步杀虫活性测试结果表明:在500 mg/L下,大部分目标化合物对斜纹夜蛾Prodenia litura和粘虫Mythimna sepatara具有一定的杀虫活性,其中ZJ11对粘虫的致死率达100%,即使在100 mg/L下,其致死率仍达80%。     

Synthesis and insecticidal activity of new pyrethroids

BACKGROUND: Pyrethroids are among the most potent pesticides known, with great potential for structural variation with retention or enhancement of potency. The simple methyl ester is easier to prepare (at least one step shorter) than the more complex pyrethroids modified on the alcohol moiety. The objective was to synthesise methyl esters of pyrethroid acids containing an aromatic ring on the acid moiety and evaluate their biological activity against Ascia monuste orseis Latr., Tuta absoluta Meyrick, Periplaneta americana (L.), Musca domestica L. and Sitophilus zeamais (Motsch.). RESULTS: The synthetic sequence required seven steps: protection of the hydroxyl groups of D ‐mannitol, diol oxidative cleavage with sodium metaperiodate, alkene formation by Wittig reaction with methoxycarbonylmethylidene(triphenyl)phosphorane, cyclopropanation, acetal hydrolysis with perchloric acid and oxidative cleavage with sodium metaperiodate gave methyl (1S, 3S)‐3‐formyl‐2,2‐dimethylcyclopropane‐1‐carboxylate. The final step comprised reaction of the aldehyde with five different aromatic phosphorus ylides to give the pyrethroids. CONCLUSION: An efficient and versatile synthesis of ten new pyrethroid methyl esters has been accomplished from the readily available D ‐mannitol in seven steps. All compounds showed insecticidal activity, and methyl (1S, 3S)‐3‐[(Z)‐2‐(4‐chlorophenyl)vinyl]‐2,2‐dimethylcyclopropane‐1‐carboxylate was the most active, killing 90% of A. monuste orseis and 100% of T. absoluta and P. americana. Copyright © 2009 Society of Chemical Industry     

Structure and insecticidal activity of picrotoxinin analogs

Picrotoxinin, a convulsant in mammals, was nontoxic when topically applied on whole house flies. When synergized with piperonyl butoxide, the topical LD₅₀ of picrotoxinin on house flies was 6.50 μg/g or 260 times less toxic on house flies than the synergized insecticide, carbofuran, a carbamate cholinesterase inhibitor.When perfused on the isolated thoracic ganglion of house fly, picrotoxinin was less potent in producing convulsions than carbofuran; however, when assayed on the desheathed thoracic ganglion, picrotoxin was more potent than carbofuran. This suggested a substantial barrier to picrotoxinin preventing diffusion into the house fly central nervous system.Of several picrotoxinin analogs synthesized the 2-iodo,4-isopropyl, 6-methylenebromidecyclohexane-γ-lactone was the most potent convulsant.     

辣椒碱类似物的合成及杀虫活性

基于辣椒碱结构,以取代苄胺为原料,经N-酰化反应合成了6个系列204个辣椒碱类似物,其中8个为新化合物。通过核磁共振氢谱 (1H NMR) 对化合物的结构进行了确证。采用叶碟法测定了目标化合物的杀虫活性。结果表明:大部分化合物在10 μg/ 片下对供试的3龄东方黏虫Mythimna separata有较强的毒杀活性,其中化合物 A30 、 D20 、 D30 、 D35 、 E30 和 F30 48 h的致死率达100%,化合物 D19 、 D21 、 D22 、 D23 、 D31 和 E31 48 h的致死率在90%以上。初步构效关系表明,苄胺苯环上氟原子单取代衍生物的杀虫活性优于氟原子双取代衍生物,其中以2-氟苄胺衍生物 ( D 系列) 杀虫活性较好;此外,酰基为2-噻吩甲酰时的杀虫活性明显优于其他取代基,表明酰基对该类化合物的杀虫活性也有显著影响。     

The fate and insecticidal activity of pirimiphos-methyl in stored wheat grain

The degradation of [¹⁴C]pirimiphos-methyl was investigated on a 1-kg bulk of grain stored in the laboratory at 15°C for 28 weeks. Breakdown of pirimiphos-methyl was slow, leaving 77% of the applied dose unchanged at the end of the experiment. The major degradation product was the hydroxypyrimidine (up to 12.5% of the applied dose) with the remainder of the residue (up to 12.1%) remaining within the grain tissues after solvent extraction. The efficacy of the treatment was assessed in a parallel experiment by bioassay of a 5-kg bulk of grain dosed with unlabelled pirimiphos-methyl. 100% Mortality of an organophosphateresistant strain of Oryzaephilus surinamensis L. was maintained throughout the experiment whereas some survival of an organophosphate-resistant strain of Tribolium castanewm (Herbst) occurred after 12 weeks of storage. This increased to give a 20% survival rate at the end of the experiment.     

含肟醚并取代异 NFDA1唑环的氨基甲酸酯类化合物的合成及生物活性

为寻找具有优异生物活性的氨基甲酸酯类化合物,根据活性亚结构拼接原理,将取代异 NFDA1 唑和肟醚基团引入多菌灵结构中,以取代苯甲醛 (1) 和2-氯苄胺(3) 为起始原料,经多步反应设计合成了10个未见文献报道的含肟醚并取代异 NFDA1 唑的氨基甲酸酯类化合物,其结构经 1H NMR 和 MS 确证。初步生物活性测定结果表明,部分目标化合物不仅具有一定的杀菌活性,同时还具有较好的除草活性。其中,活体盆栽试验结果表明,化合物11b对黄瓜霜霉病Pseudoperonospora cubensis 的相对防效为90%,对黄瓜白粉病Sphaerotheca fuliginea 的相对防效达95%,低于对照药剂多菌灵;除草活性皿测法表明,化合物11c和11j 200 mg/L下对靶标作物的根、茎抑制率均达80%以上,与对照药剂异丙酯草醚活性相当。盆栽法表明,150 g/hm2下,化合物11c和11j对繁缕Stellaria media苗前和苗后的抑制率均在70%以上,低于异丙酯草醚。此类化合物的构效关系有待进一步研究。     

新型氯虫苯甲酰胺衍生物的合成及其杀虫活性

以氯虫苯甲酰胺为先导,设计并合成了一系列结构新颖的邻氨基苯甲酰胺类衍生物,其结构均经核磁共振氢谱和质谱确证。初步杀虫活性测试结果表明,在质量浓度为1μg/mL时,部分化合物对小菜蛾Plutella xylostella的致死率均超过90%,高于先导化合物氯虫苯甲酰胺。     

3-丙烯酰胺类化合物的合成及杀虫活性

以3,4-亚甲二氧基苯酚(芝麻酚)为原料,经醚化、Vilsmeier反应、Horner反应、酰胺化等步骤制备了12个未见文献报道的3-(3,4-亚甲二氧基-6-烷氧基)丙烯酰胺类化合物,所有化合物的结构均经红外光谱、质谱、1H NMR确证。初步的杀虫活性测试结果表明:化合物 5a~5l 对粘虫3龄幼虫均有一定的杀虫活性,其中化合物 5h和5j 在150 mg/L质量浓度下对粘虫3龄幼虫的校正死亡率分别为50.0%和66.7%。     

靶向蜕皮激素受体的新型4,5,6,7-四氢-2H-吲唑酰肼类衍生物的设计、合成及杀虫活性

为了发现结构新颖的昆虫生长调节剂,以蜕皮激素受体(EcR)为靶标,以课题组发现的高活性化合物C(N-(4-(叔丁基)苯基)-2-苯基-2,4,5,6,7,8-六氢环庚基[C]吡唑-3-甲酰胺)为先导化合物,利用活性亚结构拼接的方法,设计合成了25个未见文献报道的新型4,5,6,7-四氢-2H-吲唑酰肼类衍生物,其结构经...