- Synthesis, insecticidal activity, crystal structure, and molecular docking studies of nitenpyram analogues with an ω-hydroxyalkyl ester arm anchored on the tetrahydropyrimidine ring
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On the basis of the research of the proposed modes of action between neonicotinoids and insect nicotinic acetylcholine receptor (nAChR), a new series of nitenpyram analogues with an ω-hydroxyalkyl ester arm anchored on the tetrahydropyrimidine ring was designed and synthesized to further enhance the strength of the hydrogen-bonding action they display in binding with the nAChR. The structures of the target compounds were characterized by 1H NMR, IR, and elemental analysis, and the cis configuration was confirmed by X-ray diffraction. Preliminary bioassays indicated that all of the nitenpyram analogues exhibited good insecticidal activity against Nilaparvata lugens and Myzus persicae at 100 mg/L, whereas analogues 4d and 6a afforded the best in vitro activity that had ≥95% mortality at 4 mg/L; the LC50 values of the analogues 4d and 6a were 0.170 and 0.154 mg/L, respectively. Structure-activity relationship (SAR) studies suggested that their insecticidal potency was also dual-controlled by the flexibility and size of the molecule. In addition, molecular docking simulations revealed that analogues 4d and 6a displayed stronger hydrogen-bonding action in binding with the nAChR, which explained the SARs observed in vitro and implied that the designed nitenpyram analogues are both practical and feasible.
- Sun, Chuan-Wen,Fang, Ting,Wang, Jing,Hao, Zhi-Bing,Nan, Shi-Bing
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Read Online
- Nitenpyram degradation in finished drinking water
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Rationale: Neonicotinoid pesticides and their metabolites have been indicated as contributing factors in the decline of honey bee colonies. A thorough understanding of neonicotinoid toxicity requires knowledge of their metabolites and environmental breakdown products. This work investigated the rapid degradation of the neonicotinoid nitenpyram in finished drinking water. Methods: Nitenpyram reaction products were characterized using liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOFMS). A software algorithm that compared degraded and control samples was utilized to facilitate efficient data reduction. Fragmentation pathways for six reaction products and nitenpyram were proposed using predictive software and manual product ion analysis. Results: This study showed that nitenpyram degradation in unpreserved finished drinking water was likely the result of oxidation, hydrolysis and reaction with Cl2. Structures for six nitenpyram reaction products were proposed that suggest the C9/C11 olefin as the key reactive site. Conclusions: Similarities between the identified nitenpyram reaction products and imidacloprid metabolites highlight the importance of this study, as the toxicity of neonicotinoids to pollinators has been linked to their metabolites. Based on the proposed reaction mechanisms, the identified nitenpyram reaction products in finished drinking water could also be present in the environment and water treatment facilities. As such, identifying these degradation products will aid in evaluating the environmental impact of neonicotinoid pesticides. Copyright
- Noestheden, Matthew,Roberts, Simon,Hao, Chunyan
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p. 1653 - 1661
(2016/08/28)
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- Nitrogenous heterocyclic compound and use thereof
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The invention relates to a nitrogenous heterocyclic compound with a novel structure and use thereof. The nitrogenous heterocyclic compound is a compound represented by a formula I (shown in the description) or a salt thereof acceptable in pesticide science. The nitrogenous heterocyclic compound provided by the invention can serve as a pesticide. Compared with the existing pesticides, the pesticide provided by the invention has the advantages that the chemical stability is better, and meanwhile, the killing activity to resistant insects is better.
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Paragraph 0136; 0137; 0138; 0139
(2016/10/27)
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- Improved preparation method of nitenpyram
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The invention relates to an improved preparation method of nitenpyram. The method comprises steps as follows: firstly, 1,1-dichloroethylene has a reaction with a nitration agent comprising hydrochloric acid and sodium nitrate to generate 1,1,1-trichlorine-2-nitroethane, and the 1,1,1-trichlorine-2-nitroethane has an elimination reaction with NaHCO3 to generate a 1,1-dichlorine-2-nitroethylene intermediate; secondly, 2-chlorine-5-chloromethylpyridine has a reaction with ethylamine, and an ethylamine intermediate is prepared; thirdly, the ethylamine intermediate has a reaction with 1,1-dichlorine-2-nitroethylene intermediate and monomethylamine, and the final product nitenpyram is generated. NaNO3 is used to replace traditional nitric acid to serve as a target phase transfer catalyst, the reaction selectivity is improved, the yield is higher, and the operation is safer.
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Paragraph 0050; 0051; 0052; 0053; 0054; 0055; 0056; 0057
(2016/10/07)
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- Pyridine methylamino pyridine compound and method for preparing the same
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The invention discloses a picolinate amino pyridine compound which is shown in the formula (I) and has sterilizing, insect/mite killing and weeding bioactivity as well as a preparation method thereof, a sterilizing, insect/mite killing and weeding herbicide composition containing the compound, and an application and method for controlling fungi, insects/mites and weeds by using the compound.
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Paragraph 0079; 0080; 0081; 0101; 0102
(2016/10/07)
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- Design, synthesis, and particular biological behaviors of chain-opening nitromethylene neonicotinoids with cis configuration
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On the basis of the structure of heterocyclic-fused cis configuration derivatives and chain-opening neonicotinoids, two series of novel chain-opening tetrahydropyridine analogues were designed and synthesized. The preliminary bioassay tests were determined on cowpea aphid (Aphis craccivora) and armyworm (Pseudaletia separata Walker). The results showed that some of the target compounds exhibited repellent effects, whereas others showed good insecticidal activities.
- Lu, Siyuan,Shao, Xusheng,Li, Zhong,Xu, Zhiping,Zhao, Shishuai,Wu, Yinli,Xu, Xiaoyong
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scheme or table
p. 322 - 330
(2012/04/04)
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- NITROGENOUS HETEROCYCLIC COMPOUND WITH INSECTICIDAL ACTIVITY AND ITS PREPARATION AND USE
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The present invention relates to nitro-containing heterocyclic or ring-opening nitrogenous compounds of formula (A), wherein R1, R2, R3, R4, R5, Y, Z, and W are as defined in the specification. The present invention discloses the preparation and the uses of a novel insecticide. Said compound and the derivatives thereof have high insecticidal activity to farm insects including homoptera and lepidoptera pests, such as aphis, fulgorides, aleyrodids, leafhopper, commom thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm, armywom and so on.
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Page/Page column 13
(2011/02/26)
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- HETEROCYCLIC NITROGENOUS OR OXYGENOUS COMPOUNDS WITH INSECTICIDAL ACTIVITY FORMED FROM DIALDEHYDES AND THEIR PREPARATION AND USES THEREOF
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The heterocyclic nitrogenous or oxygenous compounds of formula (A), (B), (C) or (D) formed from dialdehydes, their optical isomers, cis- and trans- isomers, or agrochemically acceptable salts, their preparation methods, agrochemical compositions comprising the compounds and the uses thereof are provided. The compounds and their derivatives have high insecticidal activities to several farming and forestry pests including homoptera and lepidoptera pests, such as aphis, fulgorid, whitefly, leafhopper, common thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm, armyworm and so on.
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Page/Page column 9; 10
(2011/11/01)
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- HETEROCYCLIC NITROGENOUS OR OXYGENOUS COMPOUNDS WITH INSECTICIDAL ACTIVITY FORMED FROM DIALDEHYDES AND THEIR PREPARATION AND USES THEREOF
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The heterocyclic nitrogenous or oxygenous compounds of formula (A), (B), (C) or (D) formed from dialdehydes, their optical isomers, cis- and trans- isomers, or agrochemically acceptable salts, their preparation methods, agrochemical compositions comprising the compounds and the uses thereof are provided. The compounds and their derivatives have high insecticidal activities to several farming and forestry pests including homoptera and lepidoptera pests, such as aphis, fulgorid, whitefly, leafhopper, common thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm, armyworm and so on.
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Page/Page column 7
(2011/11/12)
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- Synthesis, insecticidal activity, and molecular docking studies of nitenpyram analogues with a flexible ester arm anchored on tetrahydropyrimidine ring
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To make further researches on the structure-activity relationships (SARs) of our previous synthesized neonicotinoid compounds, a new series of nitenpyam analogues with flexible ester arm were synthesized. Preliminary bioassays indicated that all of our newly designed nitenpyam analogues exhibited good insecticidal activity at 100 mg/L, while analogues 4c and 4d afforded the best in vitro activity, and both of them had 100% mortality at 20 mg/L. The SAR studies suggested that their insecticidal potency was dual-controlled by the length of the ester arm and the size of the ester group. In addition, the molecular docking simulations revealed that the structural uniqueness of these analogues may lead to a unique molecular recognition and binding mode, which explained the SARs observed in vitro, and shed light on the novel insecticidal mechanism of these novel nitenpyam analogues.
- Sun, Chuanwen,Xu, Xiao,Xu, Yonghua,Yan, Dingrong,Fang, Ting,Liu, Tianyan
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scheme or table
p. 4828 - 4835
(2011/11/29)
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- NITROGENOUS HETEROCYCLIC COMPOUNDS WITH INSECTICIDAL ACTIVITY, AND THE PREPARATION AND USE THEREOF
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The present invention relates to nitro-containing heterocyclic or ring-opening nitrogenous compounds of formula (A), wherein R1, R2, R3, R4, R5, Y, Z, and W are as defined in the specification. The present invention discloses the preparation and the uses of a novel insecticide. Said compound and the derivatives thereof have high insecticidal activity to farm insects including homoptera and Lepidoptera pests, such as aphis, fulgorides, aleyrodids, leafhopper, commom thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm, armyworn and so on.
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Page/Page column 9; 10
(2010/12/29)
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- Discovery of bis-aromatic ring neonicotinoid analogues fixed as cis-configuration: Synthesis, insecticidal activities, and molecular docking studies
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A novel series of bis-aromatic ring neonicotinoid analogues (1a-1l, 2a-2c), were designed and prepared by introducing a new substituted aromatic ring into nitenpyram and forming a tetrahydropyrimidine ring, with the cis-configuration confirmed by X-ray diffraction. Preliminary bioassays showed most analogues exhibited good insecticidal activities at 100 mg/L, and compound 1d and 2a were highly potent even at 10 mg/L. Modeling the ligand-receptor complexes by molecular docking study explained the structure-activity relationships observed in vitro, which may provide some useful information for future design of new insecticides.
- Sun, Chuanwen,Jin, Jia,Zhu, Jun,Wang, Haifeng,Yang, Dingrong,Xing, Jiahua
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scheme or table
p. 3301 - 3305
(2010/08/06)
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- Method for producing 5-aminomethyl-2-chloropyridines
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PCT No. PCT/EP98/01163 Sec. 371 Date Sep. 10, 1999 Sec. 102(e) Date Sep. 10, 1999 PCT Filed Mar. 2, 1998 PCT Pub. No. WO98/41504 PCT Pub. Date Sep. 24, 1998The present invention relates to the preparation of 5-aminomethyl-2-chloropyridines by reacting a mixture of 5-chloromethyl-2-chloropyridine and 5-dichloromethyl-2-chloropyridine with substituted amines. The mixture of 5-chloromethyl-2-chloropyridine and 5-dichloromethyl-2-chloropyridine is obtained by chlorination of 5-methyl-2-chloropyridine.
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- Process for the preparation of 2-chloro-5-alkylaminomethyl-pyridines
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The invention relates to a new process for the preparation of 2-chloro-5-alkylaminomethyl-pyridines of the formula (I) STR1 in which R represents alkyl. In this process, 2-chloro-5-aminomethyl-pyridine is reacted with formic acid at temperatures between 20° C. and 200° C., if appropriate in the presence of a diluent, the 2-chloro-5-formylaminomethyl-pyridine which has been formed in this process is reacted without intermediate isolation (in situ) with alkylating agents at temperatures between 0° C. and 100° C., if appropriate in the presence of an acid acceptor, if appropriate in the presence of a diluent, and, finally, the 2-chloro-5-(N-alkyl-N-formyl-aminomethyl)-pyridines thus formed of the general formula (V) STR2 in which R has the abovementioned meaning, are reacted with aqueous alkali metal hydroxide solution at temperatures between 20° C. and reflux temperature, if appropriate after volatile components have been distilled off. The compounds (I) are, for example, intermediates for the preparation of insecticidally active substances.
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- Process for preparing a 2-chloro-5-aminomethyl-pyridine
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A 2-Chloro-5-aminomethylpyridine is prepared in one step by reacting 2-chloro-5-trichloromethylpyridine with an amine and hydrogen in the presence of a hydrogenation catalyst.
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