- Process improvements for the preparation of insecticide clothianidin
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This article describes the process improvements for the preparation of the insecticide clothianidin 1. (Z)-1-Methyl-N-nitro-5-propyl-1,3,5-triazinan-2- imine (9) which was obtained by Mannich reaction of (Z)-1-methyl-2- nitroguanidine (5) n-Propylamine an
- Wang, Qin,Wu, Yi,Wang, Kunyan,Sun, Yanxue,Zhu, Hongjun,Yu, Juan,Xu, Chaohang
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Read Online
- Insensitive nitrogen-rich materials incorporating the nitroguanidyl functionality
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A new class of nitroguanidylfunctionalized nitrogen-rich materials derived from 1,3,5-triazine and 1,2,4,5- tetrazine was synthesized through reactions between N-nitroso-N'-alkylguanidines and the hydrazine derivatives of 1,3,5-triazine or 1,2,4,5-tetrazine. These compounds were fully characterized using multinuclear NMR and IR spectroscopies, elemental analysis, and differential scanning calorimetry (DSC). The heats of formation for all compounds were calculated with Gaussian 03 and then combined with experimental densities to determine the detonation pressures (P) and velocities (D v) of the energetic materials. Interestingly, some of the compounds exhibit an energetic performance (P and Dv) comparable to that of RDX, thus holding promise for application as energetic materials. Copyright
- Zhang, Qinghua,He, Chunlin,Yin, Ping,Shreeve, Jean'Ne M.
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Read Online
- Thiamethoxam production method and extractant
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The invention provides a thiamethoxam production method and an extractant, belongs to the technical field of pesticides, particularly provides an extractant taking ethylene glycol salicylate as a complexing agent, and also provides a composite extractant. The extractant comprises a complexing agent and a diluent, and the complexing agent comprises the ethylene glycol salicylate and P204, wherein the extraction ratio of ethylene glycol salicylate to P204 is 1:1.5 to 1:2. The ethylene glycol salicylate used as the complexing agent and -N- of thiamethoxam have strong ion association to generate an ion extract with the same structure, so that the distribution ratio is increased; and when the extractant and the P204 are used for composite extraction, hydrogen bond association of the strong electron withdrawing group nitro -NO2 of thiamethoxam and -OH of P204 can be promoted, and when the extraction ratio of ethylene glycol salicylate to the P204 extractant is 1:(1.5-2), the distribution ratio can be synergistically increased, and the extraction rate is increased.
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Paragraph 0088-0089; 0094-0095
(2020/05/01)
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- Method for preparing 1-methyl-3-nitroguanidine
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The invention discloses a method for preparing 1-methyl-3-nitroguanidine. The method comprises the following steps: weighing of process water (mother liquor), methylamine and nitroguanidine, and stirring at a low temperature; gradient heating, heat preservation, and vacuum deamination; and reduction of the temperature of the system, centrifuging and filtering, reusing of the washing solution and the mother liquor, and drying for obtaining the 1-methyl-3-nitroguanidine. The method has the advantages of no acid, low reaction temperature, recyclability of ammonia gas generated by a byproduct, cycle use of the mother liquor and the washing solution, energy saving, environmental protection, white form of the finished product, improvement of the yield and purity, and great values in the field oflow-energy consumption green chemical engineering production.
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Paragraph 0036-0051; 0053; 0055
(2019/10/01)
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- Preparation method of methyl nitroguanidine
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The invention relates to a preparation method of methyl nitroguanidine. The preparation method comprises the following steps: (1) adding a methylamine water solution with mass concentration of 40%, 20-30g of water and a polyethylene glycol catalyst with mass concentration of 1% into a 500ml round-bottom flask, then dropwise adding concentrated sulphuric acid, controlling the temperature of the system to be lower than or equal to 45 DEG C, and adding nitroguanidine into the reaction system after the dropwise addition of the concentrated sulphuric acid is finished; (2) after the addition of the nitroguanidine is finished, carrying out heat preservation for 1.5-2h under the condition that the temperature of the system is lower than or equal to 45 DEG C; after heat preservation is finished, neutralizing the product until the pH value is equal to 6.5 by using dilute sulphuric acid with mass concentration of 60%, then cooling to 10-15 DEG C, filtering, and washing to obtain a methyl nitro crude product; (3) beating the methyl nitro crude product, obtained in the step (2), together with water, recrystalizing, heating up to 85-90 DEG C, carrying out thermal filtration, cooling, filtering, and drying to obtain white solid. The preparation method provided by the invention has the advantages that the method not only can guarantee the purity of the methyl nitroguanidine, but also greatly increases the molar yield of the methyl nitroguanidine.
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Paragraph 0021-0023; 0025
(2017/12/27)
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- A N-methyl-N ' nitroguanideine synthesis process
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The invention belongs to the technical field of pesticide intermediates, and relates to a N-methyl-N'nitroguanidine synthesis process, which comprises: (1) pouring fuming nitric acid and concentrated sulfuric acid into a reaction bottle, and adding S-methyl isothiourea sulfate under a stirring condition; (2) after completing the reaction, adding ice, carrying out suction filtration, and carrying out vacuum drying to obtain N-nitro methylthiourea powder; (3) pouring methanol into the reaction bottle, adding the dried N-nitro methylthiourea, and adding a methylamine alcohol solution in a dropwise manner at a room temperature; and (4) carrying out a reaction for 3 h at a temperature of 80 DEG C, filtering while hot, cooling, carrying out suction filtration, and carrying out vacuum drying on the filter cake to obtain the N-methyl-N'nitroguanidine solid. According to the process, the reaction condition is optimized, the cost is saved, and the total yield is increased to 85%.
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Paragraph 0014-0019
(2017/02/17)
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- Mannich-type reaction for synthesis of 3-methyl-4-nitroimino-tetrahydro-1, 3,5-oxadiazine
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The reaction of N-methyl-N-nitroguanidine with 3-methyl-4-nitroimino- tetrahydro-1,3,5-oxadiazine is a Mannich-type reaction. The reaction was catalyzed by several organic and inorganic bases at different reaction times and temperatures. Three inorganic base catalysts [potassium carbonate (K 2CO3), sodium hydrogen carbonate (NaHCO3), and sodium hydroxide (NaOH)] and several organic bases (methylamine, ethamine, iso-propylamine, and n-butylamine) have been studied. The results showed that both the inorganic and organic base catalysts can be used as catalysts, with the organic bases performing better. N-Methyl-N′-nitroguanidine reacts to give the title compound 2 and is catalyzed by both acids and bases. The intensity of inorganic base catalysts, reaction temperature, and reaction time had significant effects on the products.
- Qu, Wen-Yan,She, Dong-Mei,Zhao, Jian,Lin, De-Jie,Huang, Qi-Liang,Li, Feng-Min
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experimental part
p. 1950 - 1958
(2012/06/18)
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- Design, synthesis, and insecticidal activity of 1,5-diphenyl-1-pentanone analogues
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Three series of novel 1,5-diphenyl-1-pentanone derivatives were designed and synthesized. Their structures were characterized by IR, 1H NMR techniques, and elemental analysis. The insecticidal activities of the new compounds were preliminarily evaluated. The bioassay results indicated that the compounds X11-X30 displayed better aphicidal activity against Aphis gossypii than compounds X1-X10 and the lead compound (E)-1,5-diphenyl-1-penten-1-one (A). The inhibitory rates of compounds X6 and X29 were 100% against Plutella xylostella (L.) at 600 mg·L-1. Compounds X12, X13, X19, X24, X25, X26 and X27 showed higher insecticidal activity against Tetranychus cinnabarinus (Boisduval) at 600 mg·L-1 than the lead compound (A).
- Yang, Shaoxiang,Kang, Tieniu,Rui, Changhui,Yang, Xinling,Sun, Yufeng,Cui, Zining,Ling, Yun
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experimental part
p. 2394 - 2400
(2012/02/04)
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- Thermal behavior and nucleation kinetics of 1,5-dimethyl-2-nitroimino-1, 3, 5-triazinane crystal
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Nitroguanidine derivatives have increasingly gained attention because of their high insecticidal activities and wide spectrum. In this paper, nitroguanidine derivative 1,5-dimethyl-2-nitroimino-1, 3, 5-triazinane was synthesized, and its crystal structure was determined by X-ray technique. The thermal behaviors of 1, 5-dimethyl-2-nitroimino-1, 3, 5-triazinane in a nitrogen atmosphere were also studied under non-isothermal conditions by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. The TG and DSC studies showed that the sample started to melt at 408.1 K with high melting enthalpy of 121.3 J/g and was stable up to at least 423.2 K, which indicated that the sample could be effectively utilized for various devices below 423.2 K. The melting entropy of 1,5-dimethyl-2-nitroimino-1, 3, 5-triazinane calculated from melting point and melting enthalpy using Eq. (1) was 51.476 J mol-1 K-1. In addition, the nucleation parameters of 1,5-dimethyl-2-nitroimino-1, 3, 5-triazinane in ethanol, such as the radius of critical nucleus and the Gibbs free energy barrier, had also been investigated based on classical nucleation theory. Crown Copyright
- Hu, Yonghong,Chen, Xiao,Yang, Wenge,Lei, Ziyu,Zhao, Cong
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experimental part
p. 170 - 174
(2010/06/18)
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- IMPROVED METHOD FOR PRODUCING NITROISOUREA DERIVATIVE
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Disclosed is an improved process for producing nitroisourea derivatives which is necessary for producing nitroguanidine derivatives having an insecticidal activity. Specifically disclosed is a process for producing nitroisourea derivatives represented by the following general formula (3), which is characterized in that nitroisourea derivatives represented by the following general formula (1) and amines represented by the following general formula (2) or a salt thereof are reacted in the presence of a catalytic amount of a hydrogen carbonate,
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Page/Page column 5
(2008/12/04)
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- Synthesis and properties of thiamethoxam and related compounds
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The neonicotinoids are the most successful chemical class of insecticides reaching sales of more than $1 billion in 2003, mainly due to the excellent market performance of imidacloprid and thiamethoxam. This paper describes the discovery, the synthesis and the insecticidal activity of thiamethoxam and related compounds and reports the hydrolytic stability and the degradation pathways of thiamethoxam together with the synthesis of the degradation products.
- Maienfisch, Peter
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p. 353 - 359
(2007/10/03)
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- METHOD FOR PRODUCING 1-METHYL-3-NITROGUANIDINE
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The invention relates to a method for producing 1-methyl-3-nitroguanidine, comprising the following steps: a) reacting chlorine cyanide or bromine cyanide with methylamine in the presence of an inert organic solvent at temperatures of -30 to 0 DEG C; then b) allowing the methylcyanamide formed in step a) to react directly with amoniumnitrate in a temperature range of 80 to 180 DEG C and a pressure range of between 1 and 50 bar, without further reprocessing; and c) dehydrating the methylguanidine nitrate formed in step b) after removing the solvent at temperatures of -20 to 60 DEG C; and d) finally, isolating the 1-methyl-3-nitroguanidine formed in step c). The inventive method provides a particularly environmently friendly and technically simple means of producing 1-methyl-3-nitroguanidine in yields of at least 85 % and with more than 98 % purity, from economical starting materials.
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- Synthesis and Some Properties of 1,2-Dinitroguanidine
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1,2-Dinitroguanidine is a product of nitroguanidine nitration with nitric acid and its mixtures with sulfuric acid and oleum. It is a diacid (pK a 1.11, ～11.5) and at the same time a weak base undergoing protonation at the nitrogen of the amino group (pKBH+ -5.81). The decomposition kinetics of 1,2-dinitroguanidine was studied by spectrophotometric method both in acid and alkaline media, and the mechanism of the process was assumed. In the media of high acidity (Ho > -8) the 1,2-dinitroguanidine suffers reversible denitration into nitroguanidine. At lower acidity its conjugate acid or molecular form undergoes hydrolysis yielding nitrourea. Monoanion of 1,2-dinitroguanidine in a weak acid or in an alkali is hydrolyzed into N,N′-dinitrourea. The reaction of 1,2-dinitroguanidine with alkali in alcohol provides its salts, with nitrogen-containing bases form both salts and derivatives of 2-nitroguanidine. The treatment of 1,2-dinitroguanidine with haloalkanes results in its N-alkylated products.
- Astrat'yev,Dashko,Kuznetsov
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p. 501 - 512
(2007/10/03)
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- Synthesis and insecticidal activity of neonicotinoids derivatives
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A new class of compounds- neonicotinoids containing oxadiazole -were synthesized and characterized by using 1H NMR, IR, MS and Elemental Analysis. Their insecticidal activities were tested against Mythimna separata Walker and Aphis rumicis Linnaeus, some of them showed some insecticidal activity.
- Chai, Bing,Cao, Song,Liu, Haidong,Song, Gonghua,Qian, Xuhong
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p. 601 - 606
(2007/10/03)
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- The discovery of thiamethoxam: A second-generation neonicotinoid
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Neonicotinoids represent a novel and distinct chemical class of insecticides with remarkable chemical and biological properties. In 1985, a research programme was started in this field, in which novel nitroimino heterocycles were designed, prepared and assayed for insecticidal activity. The methodology for the synthesis of 2-nitroimino-hexahydro-1,3,5-triazines, 4-nitroimino-1,3,5-oxadiazinanes and 4-nitroimino-1,3,5-thiadiazinanes is outlined. Bioassays demonstrated that 3-(6-chloropyridin-3-ylmethyl)-4-nitroimino-1,3,5-oxadiazinane exhibited better insecticidal activity than the corresponding 2-nitroimino-hexahydro-1,3,5-triazine and 4-nitroimino-1,3,5-thiadiazinane. In most tests, this compound was equally or only slightly less active than imidacloprid. A series of structural modifications on this lead structure revealed that replacement of the 6-chloro-3-pyridyl group by a 2-chloro-5-thiazolyl moiety resulted in a strong increase of activity against chewing insects, whereas the introduction of a methyl group as pharmacophore substituent increased activity against sucking pests. The combination of these two favourable modifications led to thiamethoxam (CGA 293 343). Thiamethoxam is the first commercially available second-generation neonicotinoid and belongs to the thianicotinyl sub-class. It is marketed under the trademarks Actara for foliar and soil treatment and Cruiser for seed treatment. The compound has broad-spectrum insecticidal activity and offers excellent control of a wide variety of commercially important pests in many crops. Low use rates, flexible application methods, excellent efficacy and the favourable safety profile make this new insecticide well-suited for modern integrated pest management programmes in many cropping systems.
- Maienfisch, Peter,Huerlimann, Hanspeter,Rindlisbacher, Alfred,Gsell, Laurenz,Dettwiler, Hansruedi,Haettenschwiler, Joerg,Sieger, Evelyne,Walti, Markus
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p. 165 - 176
(2007/10/03)
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- A novel method for the preparation of N,N'-disubstituted-N'-nitroguanidines, including a practical synthesis of the neonicotinoid insecticide clothianidin
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A novel method is described for the synthesis of N,N'-disubstituted-N'-nitroguanidines 3 via 2-nitroimino-hexahydro-1,3,5-triazine intermediates 12, allowing the introduction of the heteroarylmethyl group either from a heteroarylmethyl amine 9 or a heteroarylmethyl chloride 14, respectively. This method enables an efficient synthesis of the neonicotinoid insecticide clothianidin (3b) in four steps from S-methyl-N-nitro-isothiourea (10). (C) 2000 Elsevier Science Ltd.
- Maienfisch,Huerlimann,Haettenschwiler
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p. 7187 - 7191
(2007/10/03)
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- Nitroisourea derivative
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A novel nitroisourea derivative and a process for producing the same, which is an important intermediate for the production of a nitroguanidine derivative having an insecticidal activity, and a process for producing a nitroguanidine derivative having an insecticidal activity using the nitroisourea derivative. The process for producing a nitroguanidine derivative represented by formula (1), effective as an insecticide is shown by reaction scheme (2): wherein R1 represents an alkyl group having from 1 to 4 carbon atoms or a benzyl group; R2 represents an alkyl group having from 1 to 4 carbon atoms; R3, R4, R5 and R6 each independently represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms; and Q represents a 5-membered or 6-membered heterocyclic ring having at least one of the following: a nitrogen atom, an oxygen atom or a sulfur atom, one of the hydrogen atoms being substitutable with a halogen atom.
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- Method for producing N-alkyl-N'-nitroguanidines
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PCT No. PCT/EP98/01428 Sec. 371 Date Sep. 22, 1999 Sec. 102(e) Date Sep. 22, 1999 PCT Filed Mar. 12, 1998 PCT Pub. No. WO98/43951 PCT Pub. Date Oct. 8, 1998The invention relates to a novel process for the preparation of N-alkyl-N'-nitroguanidines of the formula (I) in which R is C1-C6-alkyl, by neutralizing alkylamine with nitric acid, then reacting it with cyanamide, and dehydrating the alkylguanidine nitrate formed.
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- Process for preparing N-methyl-N'-nitroguanidine
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The present invention relates to a novel process for preparing N-methyl-N'-nitroguanidine by reacting nitroguanidine with aqueous methylamine solution at 0° to 40° C.
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- Thiolytic decomposition of the carcinogen N-methyl-N′-nitro-N-nitrosoguanidine. A change in rate-limiting step with nucleophile basicity controls alkylating activity
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The kinetics of the reaction of seven alkanethiolates with N-methyl-N′-nitro-N-nitrosoguanidine over the pH range 3-8.5 at 40 °C, ionic strength 1 M (KCl), are reported. Plots of kobs against total thiol concentration are linear, and the slopes of these plots change as a function of pH. The changes in slope with pH are well-described by a rate law for decomposition of MNNG that is first-order in thiolate ion and first-order in neutral MNNG. Rate constants k2′ for the reaction of the thiolates are determined. There is no significant buffer catalysis of the reactions of any of the thiolates in the pH range studied. In the case of the reactions of propanethiolate and trifluoroethanethiolate, two products, methylnitroguanidine (MNG) and the thiol ((RS)-N-nitroformamidine) adducts 1, were found to account quantitatively (98 ± 3%) for the nitroguanidine skeleton of the starting material. In the case of the other five thiolates, the percent yield of MNG was determined. The yields of MNG are independent of thiolate ion concentration or buffer concentration. The yield of MNG changes from 5% for the reaction of propanethiolate, the most basic thiolate, to 90% for the reaction of pentafluoropropanethiolate, the least basic thiolate. On the basis of the yields of MNG, which indicate the extent of reaction at the nitroso nitrogen for the different thiolates, specific second-order rate constants for the thiolate ion reaction at the nitroso nitrogen, kDN, and for the thiolate ion reaction at the guanidino carbon, kDA, are calculated from the total second-order rate constant, k2′. The plot of log kDN against pKaRSH is linear with a slope βnuc = 0.54 ± 0.02. A similar plot for log kDA shows a downward break with decreasing thiol pKa. The plot is consistent with a reaction that involves an anionic intermediate, T-, the formation of which is rate-limiting for basic thiolates and the decomposition of which is rate-limiting for weakly basic thiolates. Limiting values of βnuc consistent with the data were determined to be βnuc = 0.70 ± 0.12 and 2.4 ± 0.2 for rate-limiting formation and breakdown reactions, respectively. The latter value is attributed to a late transition state for leaving group expulsion with a large imbalance in which C-N double bond formation lags behind leaving group expulsion. The results represent a good chemical model for the recently reported chemoprotective denitrosation reaction between glutathione and MNNG that is catalyzed by a glutathione S-transferase.
- Santala, Taina,Fishbein, James C.
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p. 8852 - 8857
(2007/10/02)
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