- Methyl N-methoxyphenylcarbamate preparation method
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The invention discloses a methyl N-methoxyphenylcarbamate preparation method, which comprises: carrying out a stirring reaction on an N-hydroxyl group having a structure represented by a formula (1),an O-methylation reagent and a catalyst in an organic solvent under alkaline conditions, reducing the pressure, stopping the reaction, cooling, filtering, drying, removing the solvent, and re-crystallizing to obtain methyl N-methoxyphenylcarbamate having a structure represented by a formula (2), wherein the purity is 98.2%, the yield is 90.8%, R1 is halogen, and R2-R11 are H or C1-C5 alkyl.
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Paragraph 0038-0040
(2019/11/14)
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- IMPROVED PROCESS FOR THE PREPARATION OF PYRACLOSTROBIN
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The present invention relates to a novel and improved process for preparation of methyl [2-({[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy}methyl)phenyl]methoxycarbamate (Pyraclostrobin)of formula (I) in free form or in agrochemically acceptable salt form useful as a pest control agent starting from methyl [2-({[1-(4-chlorophenyl)-1-H-pyrazol-3-yl]oxy}methyl)phenyl]hydroxycarbamatein simple manner and in high purity and good yield.
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Page/Page column 11-12; 13; 14
(2019/08/08)
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- Preparation method for high-purity pyraclostrobin
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The invention relates to the technical field of compound synthesis, in particular to a preparation method for high-purity pyraclostrobin. The pyraclostrobin is synthesized from p-chloroaniline and o-nitrosotoluene as initial raw materials through the steps of diazotizing, cyclizing, oxidizing, bromizing, condensating, reducing, acylating, methylating and the like. According to the preparation method, the problem that the purity of the pyraclostrobin in the prior art is low is solved; and the preparation method for the pyraclostrobin has the advantages of high yield, high purity and high material utilization rate.
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- Synthesis process of pyraclostrobin
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The invention discloses a synthesis process of pyraclostrobin. The synthesis process includes the process of synthesis, cyclization, oxidization, bromination, etherification, reduction, esterificationand methylation of chlorophenylhydrazine hydrochloride. According to the synthesis process of the pyraclostrobin, when 1-(4-chlorphenyl)-3-pyrazole alcohol is prepared, air oxidization is adopted, the reaction is mild, controllability is high, and the yield is improved by 5% or above compared with literature reports; in the etherification reaction, an inorganic base water solution is adopted as the acid-binding agent, an efficient phase transfer catalyst B is added, the reaction time is effectively shortened, and the reaction yield is effectively improved; a specific catalyst C is adopted, adichloroethane and ethyl alcohol mixed solution serves as the reaction solvent, the side reaction of reducing a nitryl group into an amido group is effectively controlled, the reaction yield is greatly improved to reach 95% or above.
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Paragraph 0031; 0036-0037; 0042-0043; 0048-0049; 0054
(2019/10/01)
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- Preparation method of high-purity pyraclostrobin
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The invention provides a preparation method of high-purity pyraclostrobin. The high-purity pyraclostrobin is prepared by taking 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole and O-nitrobenzyl bromide as raw materials and through condensation, reduction, esterification, methylation and mixed solvent separation and purification. By adopting the preparation method provided by the invention to prepare thehigh-purity pyraclostrobin, the preparation method has the characteristics that the cost is low, the product purity is high, the product yield is high, the raw materials are easy to obtain, and the like; the recycling and reusing rate of a solvent required for reaction is high, the three wastes can be preferably treated, and the purpose of clean production can be achieved.
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- Based on pyraclostrobin intermediate methylation synthesis method (by machine translation)
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The invention discloses based on pyraclostrobin intermediate methylation synthetic method, pyraclostrobin intermediate with the phase transfer catalyst, solvent, alkaline solution and methyl chloride by reaction gas, controlling the reaction temperature and pressure, to be after the reaction, cooling, pyraclostrobin intermediate methylation product obtained. The invention synthetic method is to pyraclostrobin N - hydroxy intermediate to methylation method, the substitute methyl dimethyl sulfate, dimethyl carbonate, methyl iodide and the like as in the production process of the pyraclostrobin methylation reagent, effectively reduce the production cost and wastes, methylation yield ≥ 95.0%, HPLC external standard content ≥ 98.0%. (by machine translation)
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Paragraph 0069-0075
(2018/05/16)
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- Synthesis method of pyraclostrobin
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The invention relates to a synthesis method of pyraclostrobin. The method comprises the following steps: 1) adding N-hydroxy-N-2-[N-(4-chlorophenyl) pyrazolyl-3-oxymethyl]aniline and triethylamine into a reaction solution, stirring, and heating; 2) dropwisely adding iodomethane to carry out methylation reaction, and keeping the temperature; 3) neutralizing by washing with water, and standing to stratify; and 4) recovering methylbenzene, adding isopropanol, crystallizing, and filtering to obtain the pyraclostrobin pure product. The synthesis method reduces the damage to the human body and environment, and requires low acid-binding agent consumption. The method enhances the yield of the product, and further lowers the generation of byproducts. The method is simple to operate, and has the advantages of high raw material conversion rate and high yield and content (respectively 98% or above).
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Paragraph 0028; 0033-0034
(2017/07/05)
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- A novel process for preparing crystalline methyl N-[2-[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]-N-methoxycarbamate
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The present invention relates to a process for preparing crystalline methyl N-[2-[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]-N-methoxycarbamate (I), comprising a) reacting a compound of formula (II) with an alkylating agent in the presence of a base in the presence of a polar solvent selected from alcohols and ketons; b) the addition of water.
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Page/Page column 4
(2017/03/08)
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- Method for simply synthesizing pyraclostrobin
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The invention discloses a method for simply synthesizing pyraclostrobin. The method comprises steps as follows: N-hydroxyl-N-2-[1-(4-chlorophenyl)-3-pyrazoloxy methyl]phenyl carbamate and a phase transfer catalyst are dissolved in an organic solvent, dimethyl sulfate is added, an acid-binding agent is dropwise added at the system temperature kept in a range of 5-70 DEG C, the components react for 1-5 h, and pyraclostrobin is obtained. Under the condition of reasonable control of feeding sequence of reaction raw materials and the system temperature, the problems of many reaction by-products as well as potential safety hazard and the like due to the many reaction by-products in an existing pyraclostrobin synthesis process are effectively solved, and a plurality of advantages such as reduction of production cost, reduction of wastewater quantity in a production process and the like can be provided for industrial production, so that the method is beneficial to energy conservation, emission reduction and environment protection of pesticide chemical enterprises and is more suitable for large-scale industrial production.
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Paragraph 0027-0029; 0057-0059
(2017/08/29)
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- Synthesis technology of pyraclostrobin
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The invention provides a synthesis technology of pyraclostrobin. The method comprises the following steps that1, ortho-nitrotoluene and NH4Cl are subjected to a reduction reaction under the catalytic action of zinc powder and alloy micro-nano powder; 2, hydroxylamine is subjected to an acylation reaction; 3, a methylation reaction is performed; 4, a bromination reaction is performed to obtain N-methoxy-N-2-methyl bromide methyl phenyl carbamate; 5, DMF is used as a solvent for dissolving the N-methoxy-N-2-methyl bromide methyl phenyl carbamate to prepare a solution for use, 1-(4-chlorphenyl)-pyrazol alcohol, K2CO3 and acetone are placed into a reactor together, heating and reflux are performed, the N-methoxy-N-2-methyl bromide methyl phenyl carbamate solution is added into the reactor slowly, and after the reflux reaction is ended, pyraclostrobin is obtained. Compared with the prior art, the preparation method is simple, raw materials are low in cost and easy to obtain, the reaction conditions are mild, and the obtained target product is high in purity and yield.
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- Method for catalytically synthesizing pyraclostrobin
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The invention discloses a method for catalytically synthesizing pyraclostrobin, relating to the technical fields of chemical industry and pesticide intermediate preparation. The method comprises the following steps: adding a compound II N-hydroxy-N-2-[(N-p-chlorphenyl)-3-pyrazolyloxymethyl]carbanilate into a two-phase solvent, adding a phase-transfer catalyst, and meanwhile, dropwisely adding an acid-binding agent water solution and dimethyl sulfate to carry out etherification reaction on the compound II N-hydroxy-N-2-[(N-p-chlorphenyl)-3-pyrazolyloxymethyl]carbanilate and dimethyl sulfate while keeping the pH value of the reaction system at 8-9, thereby obtaining the compound I pyraclostrobin. The method has the advantages of short reaction time and high product yield, lowers the production cost, and reduces the generated wastewater, thereby being beneficial to environment protection.
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Paragraph 0019; 0021; 0028
(2016/10/31)
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- N-Carbomethoxy-N-methoxy-(2-chloromethyl)-anilines, their preparation and their use as precursors for preparing 2-(pyrazol-3'-yloxymethylene)-anilides
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The present invention relates to N-carbomethoxy-N-methoxy-(2-chloromethyl)-aniline compounds of the formula I, wherein: n is 0, 1, 2 or 3, each R1 is independently selected from halogen, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy or C1-C4-haloalkoxy. The invention also relates to processes and intermediates for preparing such compounds of formula I. The invention furthermore relates to processes for preparing 2-(pyrazol-3′-yloxymethylene)-anilides in which compounds of formula I are applied as precursors.
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- N-CARBOMETHOXY-N-METHOXY-(2-CHLOROMETHYL)-ANILINES, THEIR PREPARATION AND THEIR USE AS PRECURSORS FOR PREPARING 2-(PYRAZOL-3'-YLOXYMETHYLENE)-ANILIDES
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The present invention relates to N-carbomethoxy-N-methoxy-(2-chloromethyl)-aniline compounds of the formula I, wherein: n is 0, 1, 2 or 3, each R1 is independently selected from halogen, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4- alkoxy or C1-C4-haloalkoxy. The invention also relates to processes and intermediates for preparing such compounds of formula I. The invention furthermore relates to processes for preparing 2-(pyrazol-3'-yloxymethylene)-anilides in which compounds of formula I are applied as precursors.
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- PROCESS FOR PREPARING 1-PHENYLPYRAZOLES
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The present invention to a process for preparing 1-phenylpyrazoles of the formula I in which each R1 is independently selected from chlorine, fluorine, alkyl, haloalkyl, alkoxy and haloalkoxy;n is 1, 2 or 3;each R2 is independently selected from cyano, nitro, halogen, alkyl, haloalkyl,alkoxy, haloalkoxy,alkylthio and alkoxycarbonyl; mis 0, 1 or 2;A is alkyl, aryl or aryl-C1-C4-alkyl, where A optionally bears 1, 2, 3 or 4 substituents comprising reacting a phenyl halide of the formula (II) with apyrazole derivative of the formula (III) in which X is chlorine, iodine or bromine; and R1, n, R2, m and A are each as defined above, in the presence of a base and a catalytic system comprising a ligand and a metal compound selected from palladium compounds, iron compounds and copper compounds.
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Page/Page column 28
(2011/04/14)
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