BACKGROUND:Plant pathogenic fungi present a dual threat, leading to significant agricultural yield reductions while concurrently endangering human health. The growing resistance risk from the misuse of fungicides is driving the urgent need for novel agents with new structures and modes of action. RESULT:Based on the promising antifungal potential of the pyridine scaffold, the structural optimization of 6-methoxy-3-nitropyridin-2-amine derivatives led to the design and synthesis of 28 novel compounds. Systematic evaluation identified N-((2-chlorothiazol-5-yl) methyl) -N-ethyl-6-methoxy-3-nitropyridin-2-amine (T10), which exhibited remarkable activity against Botrytis cinerea, with in vitro and in vivo EC50 values of 0.47 and 7.30 mg/L, respectively, demonstrating performance comparable to the commercial fungicide boscalid. In addition, acute toxicity tests indicate that the oral LD50 of T10 mice is greater than 2 g/kg. Mechanistic studies via RNA sequencing preliminarily indicate that T10 exerts its antifungal effect by inhibiting the ribosome biogenesis pathway, a mode of action distinct from conventional fungicides. CONCLUSION:The results identified the 6-methoxy-N-ethyl-3-nitropyridin-2-amine scaffold as a valuable novel structural template, offering a fresh perspective for designing next-generation fungicides with innovative architectures and mechanisms. © 2026 Society of Chemical Industry.

Botrytis cinerea is one of the most destructive pathogens that cause serious damage to fruits and vegetables. The effective management of B. cinerea thus requires the continuous development of new fungicides with novel structures or distinct modes of action. This study on nitropyridine chemistry led to the discovery of 6Bc-5 (HNPC-A0073). 6Bc-5 exhibits excellent fungicidal potency against B. cinerea (EC50 = 0.47 mg/L), superior to or comparable to the commercial products, such as procymidone, boscalid, and fluopyram. Notably, 6Bc-5 probably operates through a distinct fungicidal mechanism that does not affect energy metabolism but instead potently suppresses the ribosome biogenesis pathway of pathogenic fungi. This mechanism also allows 6Bc-5 to demonstrate a low toxicity to mammals, bees, and birds.

BACKGROUND:Nicotinic acetylcholine receptor (nAChR) competitive modulators, especially neonicotinoid insecticides represented by imidacloprid and thiamethoxam, have been highly effective in controlling Aphis fabae. However, the outdoor use of imidacloprid and thiamethoxam has been banned in the European Union (EU) since 2018 due to risk to bees. Additionally, their long-term and widespread use has led to increasingly severe resistance problems. The effective management of Aphis fabae thus requires the continuous development of novel insecticides, particularly those with novel structures and low toxicity to bees. RESULTS:In the pursuit of novel insecticides, a series of nitropyridine compounds were synthesized and evaluated. Compounds 1a (6-methoxy-N-methyl-3-nitropyridin-2-amine) and 1b (6-methoxy-N,N-dimethyl-3-nitropyridin-2-amine), both containing the substructure 2-nitroethene-1,1-diamine, demonstrated insecticidal activity against Aphis fabae. Further derivatization, by replacing the methyl group of compound 1b with (2-chloropyridin-5-yl)methyl from imidacloprid or (2-chlorothiazol-5-yl)methyl from thiamethoxam, yielded compounds 2b and 3b, respectively, which displayed significantly enhanced insecticidal activity against Aphis fabae. During the optimization of compound 2b, compound 6a-4 was unexpectedly discovered as a by-product, exhibiting potent efficacy and a new 1,2,3,4-tetrahydro-6H-pyrido[1,2-a]pyrimidin-6-one structure. Further structural optimization, by introducing dihydroimidazo[1,2-a]pyridin-5(1H)-one, finally led to the discovery of three highly effective 3-nitropyridin-2-amine-based 2,3-dihydroimidazo[1,2-a]pyridin-5(1H)-one insecticides: compounds 6a-1 (1-((2-chloropyridin-5-yl)methyl)-8-nitro-2,3-dihydroimidazo[1,2-a]pyridin-5(1H)-one), 6b-1 (1-((2-chlorothiazol-5-yl)methyl)-8-nitro-2,3-dihydroimidazo[1,2-a]pyridin-5(1H)-one), and 7a-1 (1-((2-chloropyridin-5-yl)methyl)-8-nitro-2,3-dihydroimidazo[1,2-a]pyridine-5(1H)-thione). CONCLUSION:Compounds 6a-1, 6b-1, and 7a-1 exhibit excellent insecticidal activity against Aphis fabae. Their insecticidal potency is superior to or comparable to that of commercial insecticides, such as imidacloprid, nitenpyram, triflumezopyrim, and flupyrimin. Moreover, they demonstrate low toxicity to rats, bees, and fish. © 2026 Society of Chemical Industry.

Abstract BACKGROUND Nicotinic acetylcholine receptor (nAChR) competitive modulators, especially neonicotinoid insecticides represented by imidacloprid and thiamethoxam, have been highly effective in controlling Aphis fabae . However, the outdoor use of imidacloprid and thiamethoxam has been banned in the European Union (EU) since 2018 due to risk to bees. Additionally, their long‐term and widespread use has led to increasingly severe resistance problems. The effective management of Aphis fabae thus requires the continuous development of novel insecticides, particularly those with novel structures and low toxicity to bees. RESULTS In the pursuit of novel insecticides, a series of nitropyridine compounds were synthesized and evaluated. Compounds 1a (6‐methoxy‐ N ‐methyl‐3‐nitropyridin‐2‐amine) and 1b (6‐methoxy‐ N,N ‐dimethyl‐3‐nitropyridin‐2‐amine), both containing the substructure 2‐nitroethene‐1,1‐diamine, demonstrated insecticidal activity against Aphis fabae . Further derivatization, by replacing the methyl group of compound 1b with (2‐chloropyridin‐5‐yl)methyl from imidacloprid or (2‐chlorothiazol‐5‐yl)methyl from thiamethoxam, yielded compounds 2b and 3b , respectively, which displayed significantly enhanced insecticidal activity against Aphis fabae . During the optimization of compound 2b , compound 6a‐4 was unexpectedly discovered as a by‐product, exhibiting potent efficacy and a new 1,2,3,4‐tetrahydro‐6 H ‐pyrido[1,2‐a]pyrimidin‐6‐one structure. Further structural optimization, by introducing dihydroimidazo[1,2‐a]pyridin‐5(1 H )‐one, finally led to the discovery of three highly effective 3‐nitropyridin‐2‐amine‐based 2,3‐dihydroimidazo[1,2‐a]pyridin‐5(1 H )‐one insecticides: compounds 6a‐1 (1‐((2‐chloropyridin‐5‐yl)methyl)‐8‐nitro‐2,3‐dihydroimidazo[1,2‐a]pyridin‐5(1 H )‐one), 6b‐1 (1‐((2‐chlorothiazol‐5‐yl)methyl)‐8‐nitro‐2,3‐dihydroimidazo[1,2‐a]pyridin‐5(1 H )‐one), and 7a‐1 (1‐((2‐chloropyridin‐5‐yl)methyl)‐8‐nitro‐2,3‐dihydroimidazo[1,2‐a]pyridine‐5(1 H )‐thione). CONCLUSION Compounds 6a‐1 , 6b‐1 , and 7a‐1 exhibit excellent insecticidal activity against Aphis fabae . Their insecticidal potency is superior to or comparable to that of commercial insecticides, such as imidacloprid, nitenpyram, triflumezopyrim, and flupyrimin. Moreover, they demonstrate low toxicity to rats, bees, and fish. © 2026 Society of Chemical Industry.

A series of oxazole-5-carboxamide derivatives were designed as succinate dehydrogenase (SDH) inhibitors and synthesized, characterized, and evaluated for their fungicidal activities. Among these compounds, SEZA18 and SEZC7 displayed 0.17 and 0.50 mg/L EC50 values against Magnaporthe grisea in vitro, respectively, whose anti-M. grisea activities were closed to prochloraz (0.15 mg/L) and surpassed hymexazol (45.5 mg/L). Moreover, SEZA18 and SEZC7 exhibited 45.3 and 49.5% protective effects against M. grisea at the dose of 200 mg/L in vivo, whose preventive effects were about double times less than that of azoxystrobin (93%). In addition, SEZA14 possessed an EC50 value of 2.33 mg/L against Penicillium digitatum in vitro and showed 77.9% prevention effects from P. digitatum at the dose of 100 mg/L in a potted experiment, whose fungicidal activity was comparable to that of boscalid (75.5%). SEZC7 demonstrated SDH inhibitory activity (IC50 = 16.6 μM), exhibiting activity levels similar to those of boscalid (IC50 = 12.9 μM). Molecular docking results further revealed that SEZA14, SEZA18, SEZC7, and boscalid possessed a mode of action similar to that of SDH. Transcriptome analysis suggested that C7 interfered with the energy metabolism by inhibiting SDH activity, thereby affecting cellular sugar metabolism processes of M. grisea. In summary, our finding gave SDH inhibitors featuring novel structures, which provided a potential candidate for the management of plant pathogenic fungi.

Pyrimidifen is an excellent commercial acaricide, but it is not low toxic to mammals. Trifluoroethyl thioether derivatives exhibit excellent bioactivity, and flupentiofenox is the first commercially available trifluoroethyl thioether acaricide. To search for novel pesticides, we conducted research around pyrimidifen and flupentiofenox. By introducing trifluoroethyl thioether and F, Cl, CH3 substituents at different positions on the benzene ring, we successfully introduced trifluoroethyl thioether into the pyrimidine derivatives. Further optimization resulted in compound T7 (HNPC-A188)(5-chloro-6-(difluoromethyl)-N-(2-(2-fluoro-4-methyl-5-((2,2,2-trifluoroethyl)thio)phenoxy)ethyl)pyrimidin-4-amine). HNPC-A188 exhibits excellent acaricidal activity with LC50 values of 0.19 mg/L against Tetranychus urticae, which can be compared with the commercial acaricide cyenopyrafen (LC50 = 0.13 mg/L).

In order to overcome the problem of pesticide resistance, it is necessary to discover novel pesticides with new mechanisms of action. Herein, a series of novel pyrimidin-4-amine derivatives containing trifluoroethyl sulfide moiety were designed and synthesized. Bioassays indicated that the title compounds synthesized possessed excellent acaricidal activity against Tetranychus urticae and fungicidal activity against Erysiphe graminis and Puccinia sorghi. Especially, the acaricidal activity of 5-chloro-6-(difluoromethyl)-N-(2-(2-fluoro-4-methyl-5-((2,2,2-trifluoroethyl)thio)phenoxy)ethyl)pyrimidin-4-amine (compound T4, LC50 = 0.19 mg/L) against T. urticae was close to commercial acaricide cyenopyrafen, and the fungicidal activity of 5-chloro-6-(difluoromethyl)-2-methyl-N-(2-(3-((2,2,2-trifluoroethyl)thio)phenoxy)ethyl)pyrimidin-4-amine (compound T15, EC50 = 1.32 mg/L) against P. sorghi. was superior to commercial fungicide tebuconazole. The synthesis and characterization of these compounds were given and the structure-activity relationships were discussed. By connecting the key intermediate trifluoroethyl sulfide with pyrimidinamine, we obtained T4 with LC50 was 0.19 mg/L against T. urticae and T15 with EC50 was 1.32 mg/L against P. sorghi after active testing and structural optimization. image

With the increasing evolution of pesticide resistance, pyrimidinamine derivatives are considered promising agricultural compounds because of their outstanding activity and their mode of action which is different from other fungicides. But diflumetorim, the commercial pyrimidinamine fungicide, is not effective in controlling corn rust (Puccinia sorghi). In this study, a series of pyrimidinamine derivatives were designed and synthesized using pyrimidifen as a template according to the bioisosterism. The new compounds showed excellent fungicidal activity. Among these compounds, (S)-5-chloro-6-(difluoromethyl)-2-methyl-N-(1-((5-(trifluoromethyl)pyridin- 2-yl)oxy)propan-2-yl)pyrimidin-4-amine, T33, had the best control effect on corn rust with EC50 values of 0.60 mg/L, versus commercial fungicide tebuconazole (1.65 mg/L). The synthesis, characterization, and activity data of the compounds are presented in the text, and the structure-activity relationships are discussed.

Aphis fabae is a widespread pest that has more than 200 hosts in the world, belongs to hemiptera, for stinging suction mouthparts, harm buds, young leaves, and flower buds. Pyrimidine derivatives have the advantages of insecticidal, bactericidal, herbicidal, regulating plant growth and other biological activities, and have a unique mechanism of action. Pyrimidinamine derivatives, one of pyrimidine derivatives, were reported as early as 1955, and all the world's major pesticide companies (Syngenta, Dow Yinon, Bayer, DuPont, and BASF) have carried out research studies, which had lasted for nearly 60 years. For example, commercial pyrimidine products such as flupyrimethanil (fungicide) and pyrimethanil (insecticidal and acaricidal agents) show excellent biological activity. So pyrimidinamine derivatives are considered promising agricultural compounds. In this study, a series of pyrimidinamine derivatives were designed and synthesized using pyrimidifen as a template according to bioisosterism. 5-chloro-N-(1-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)-2-methylpropan-2-yl)- 6-ethylpyrimidin-4-amine, T23, had the best control effect on Aphis fabae with LC50 values of 1.46 mg/L, versus commercial insecticides spirotetramat and imidacloprid (2.45 and 0.53 mg/L). The synthesis, characterization, and activity data of the compounds are presented in the text, and the structure-activity relationships are discussed.

To search for novel pesticides, the synthesis around commercialized insecticide tebufenpyrad accidentally led us to the discovery of the fungicidal lead compound, 3-ethyl-1-methyl-N-((2-phenylthiazol-4-yl)methyl)-1H-pyrazole-5-carboxamide (1a) and its pyrimidin-4-amine-based optimization derivative 5-chloro-2,6-dimethyl-N-(1-(2-(p-tolyl)thiazol-4-yl)ethyl)pyrimidin-4-amine (2a). Compound 2a not only demonstrates fungicidal activity superior to commercial fungicides such as diflumetorim but also exhibits the good features that come with pyrimidin-4-amines, such as unique modes of action and no cross-resistance to other pesticide classes. However, 2a is highly toxic to rats. Further optimization of 2a by introducing pyridin-2-yloxy substructure finally led to the discovery of 5b5-6 (HNPC-A9229) (5-chloro-N-(1-((3-chloropyridin-2-yl)oxy)propan-2-yl)-6-(difluoromethyl)pyrimidin-4-amine). HNPC-A9229 exhibits excellent fungicidal activities with EC50 values of 0.16 mg/L against Puccinia sorghi and 1.14 mg/L against Erysiphe graminis, respectively. Not only that its fungicidal potency is significantly superior to or comparable to commercial fungicides including diflumetorim, tebuconazole, flusilazole, and isopyrazam, HNPC-A9229 possesses low toxicity to rats.

The indoor herbicidal activity of a new herbicide pyroxasulfone with soil spray blocking treatment against four main weeds in soybean fields, Abutilon theophrasti, Chenopodium album, Setaria viridis and Digitaria sanguinalis, was studied by using the indoor bioassay method, and evaluated the safety of pyroxasulfone against three soybean varieties. The results showed that pyroxasulfone had high biological activities on four kinds of weeds and had good safety for the three soybean varieties, the selectivity index was higher than 2. So it can be used as a soil sealing treatment agent in soybean field.

作为γ-氨基丁酸门控氯离子通道别构调节剂,溴虫氟苯双酰胺(Broflanilide)是目前唯一获得登记的双酰胺类杀虫剂,它不仅具有广谱、高效等活性特点,且能有效防治抗性害虫.为获得结构多样性新型双酰酰胺类杀虫活性化合物,对溴虫氟苯双酰胺进行先导结构多样性衍生,设计合成了系列新型双酰胺类化合物,其结构经1H NMR和MS等表征确证.研究结果表明,该类化合物对粘虫等鳞翅目害虫和蚜虫等半翅目害虫均具有高活性,对害螨棉红蜘蛛也具有显著活性.

[目的]建立一种测定溴氰菊酯乳油中顺式二溴菊酰氯杂质含量的高效液相色谱分析技术.[方法]采用CHIRALPAK? AD-H不锈钢柱和DAD检测器,以异辛烷:1,4-二氧六环(体积比90∶10)为流动相,在210 nm波长下对顺式二溴菊酰氯进行分析定量测定.[结果]顺式二溴菊酰氯的线性相关系数R2为0.9996,标准偏差为0.0013,变异系数RSD为2.71％,平均回收率为87.85％.[结论]该方法操作简单,分离效果良好,具有较高的准确度和精密度,线性关系良好,适用于50 g/L溴氰菊酯乳油中顺式二溴菊酰氯杂质的定量分析.

为研究嗪虫唑酰胺(Dimpropyridaz)的生物活性,以3-甲基-2-丁酮和3,4,5-三氯哒嗪为原料,经7步反应合成了嗪虫唑酰胺,其结构经质谱和核磁共振氢谱等表征确证.室内测定了嗪虫唑酰胺对蚕豆蚜虫(Aphis fabae)、稻褐飞虱(Nilaparvata lugens)、粘虫(Mythimna separate)和棉红蜘蛛(Tetranychius urticae)的生物活性,结果表明嗪虫唑酰胺对蚕豆蚜虫表现出高活性,其LC50值为0.039 mg/L,对褐飞虱表现出一定活性,对粘虫和棉红蜘蛛没有表现出明显活性.

采用喷雾法研究了新型双酰胺类化合物HNPC-A102对蓟马的田间防治效果.田间药效试验结果表明:30～60 g a.i./hm2剂量下,药后1d,HNPC-A102对茄子蓟马防效达86％以上,与同等剂量对照药剂溴氰虫酰胺相当;药后8d,HNPC-A102对茄子蓟马防效达95％以上,溴氰虫酰胺防效均不足35％;药后13d,HNPC-A102对茄子蓟马仍保持89％～95％的防治效果.HNPC-A102能够有效防治蓟马,且速效性及持效性好,对作物安全,具有进一步研究开发价值.

双酰胺类杀虫剂结构新颖多样,作用机制新颖独特,防虫效果卓越广谱.介绍了双酰胺类杀虫剂的结构类型,总结了具有应用价值进入研发程序的双酰胺类杀虫剂,并就其作用机制和抗性机理进行了分析探讨,就其环境风险进行了浅析评价,旨在为双酰胺类杀虫剂的研究、开发与应用提供支持与指导.

综述了由拜耳作物科学公司开发的新型双酰胺类杀虫剂四唑虫酰胺(Tetraniliprole)的合成方法,主要包括缩合法、胺解法和环化法等3种方法,且对这些方法所涉及的关键中间体的合成也进行了简要概述.其中,缩合法,特别是以关键中间体N,3-二甲基-2-氨基-5-氰基苯甲酰胺和1-(3-氯吡啶-2-基)-3-(5-三氟甲基-2H-四氮唑-2-亚甲基)吡唑-5-甲酸在碱和甲磺酰氯作用下直接合成四唑虫酰胺的合成路线,具有原料易得、产率高和易于操作等优点,可能是目前制备四唑虫酰胺的最佳合成工艺.

双酰胺类杀虫剂结构多样、新颖,作用机制丰富、独特,防虫效果卓越、广谱.介绍了双酰胺类杀虫剂的结构类型,总结了登记上市的双酰胺类杀虫剂及其应用、销售概况,并就双酰胺类杀虫剂防治刺吸式口器害虫前景进行了分析探讨与展望,旨在为双酰胺类杀虫剂的研究、开发与应用提供支持与指导.

自主设计、合成了系列新型邻胺基苯甲酰胺类化合物,并对其进行了杀虫活性、安全性、毒性、工艺、制剂、温室和/或田间防治效果等研究,获得了Ia、Ib和Ic等系列自主知识产权的高杀虫活性化合物.结果 表明化合物Ic等对咀嚼口器害虫如粘虫和小菜蛾等的活性较邻胺基苯甲酰胺类杀虫剂氯虫苯甲酰胺水平相当或更胜一筹,对刺吸口器害虫如蚜虫等的活性远优于氯虫苯甲酰胺及溴氰虫酰胺.田间药效试验进一步证实,Ic等对咀嚼口器害虫如水稻二化螟、稻纵卷叶螟、甜菜夜蛾等的防治效果相当于或优于氯虫苯甲酰胺,对刺吸口器害虫如蚜虫等的防治效果优于溴氰虫酰胺.新型邻胺基苯甲酰胺类化合物Ic等可作为候选杀虫剂进一步研究开发.

综述了2020年ISO公开的含氟杀虫剂cyclobutrifluram、flupentiofenox、nicofluprole和cyproflanilide及其关键中间体的合成方法,且对其进行了简要介绍.