- Design, docking, synthesis, and characterization of novel N'(2-phenoxyacetyl) nicotinohydrazide and N'(2-phenoxyacetyl)isonicotinohydrazide derivatives as anti-inflammatory and analgesic agents
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Inflammation is the complex biological response of vascular tissues, which is partly determined by prostaglandins (PLA2). The cyclooxygenase (COX) enzyme exists in two isoforms: COX-1 and COX-2 and by the action of this, the PGs are produced. Besides, nonsteroidal anti-inflammatory drugs (NSAIDs) are therapeutic agents useful in the treatment of inflammation. Encouraged by this, the new derivatives of N'(2-phenoxyacetyl)nicotinohydrazide 9(a-e) and N'(2-phenoxyacetyl)isonicotinohydrazide 10(a-e) were designed, synthesized, characterized, and identified as remarkable anti-inflammatory and analgesic agents. These compounds were prepared in a series of steps starting with different phenol derivatives. Among the series, compound (10e) showed the highest IC50 value for COX-1 inhibition, whereas compounds (9e) and (10e) exhibited the highest COX-2SI. Further, molecular Docking Studies have been performed for the potent compound to check the three-dimensional geometrical view of the ligand binding to the targeted enzymes.
- Al-Ostoot, Fares Hezam,Khanum, Shaukath Ara,M, Pallavi H,Vivek, Hamse Kameshwar
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- Preparation method of 2, 4-dichlorophenoxyacetic acid
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The invention provides a preparation method of 2, 4-dichlorophenoxyacetic acid, the preparation method comprises the following steps: A) dissolving chloroacetic acid in isopropanol, adding 2, 4-dichlorophenol and polyethylene glycol 400, adding alkali at 10-25 DEG C, and carrying out salt forming reaction; b) after the salt forming reaction is finished, raising the temperature to 80-100 DEG C and carrying out condensation reaction; and C) adding hydrochloric acid into a condensation reaction system for acidification to obtain the 2, 4-dichlorophenoxyacetic acid. The organic solvent isopropanol is adopted, so that wastewater generated by condensation reaction is reduced, the cost is reduced, and the problem of difficult treatment of phenolic wastewater is solved. The catalyst polyethylene glycol 400 is used, the yield is improved, and experimental results show that the yield of the 2, 4-dichlorphenoxyacetic acid prepared by the preparation method is 98%, and the purity is 98.6%.
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Paragraph 0053-0065
(2021/07/17)
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- Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)
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N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.
- Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
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supporting information
(2021/01/04)
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- Novel lipophilic analogues from 2,4-D and Propanil herbicides: Biological activity and kinetic studies
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This work describes the synthesis of new lipophilic amides and esters analogues of classical organochlorides herbicides by incorporation of long-chains from fatty acids and derivatives. The new fatty esters and amides were synthesized in 96–99percent and 80–89percent yields, respectively. In general, all compounds tested showed superior in vitro activity than commercial herbicides against growth L. sativa and A. cepa, in ranges 86–100percent of germinative inhibition. The target compounds showed, significantly more susceptible towards acid hydrolysis than 2,4-dichlorophenoxyacetic acid (2,4-D). The kinetic and NMR studies showed that the incorporation of lipophilic chains resulted in a decrease in half-life time of new herbicides compounds (1.5 h) than 2,4-D (3 h). These findings suggest the synthesis of new lipophilic herbicides as potential alternative to traditional formulations, by incorporation of long fatty alkyl chains in the molecular structure of 2,4-D, resulting in superior in vitro herbicidal activity, best degradation behavior and more hydrophobic derivatives.
- D'Oca, Caroline R. M.,D'Oca, Marcelo G. M.,Nachtigall, Fabiane M.,Orth, Elisa S.,Porciuncula, Larissa M.,Santos, Leonardo S.,Santos, Maria F. C.,Teixeira, Alex R.
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- Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors
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A series of aryloxyacetic acid derivatives were designed and synthesized as 4-hydoxyphenylpyruvate dioxygenase (HPPD) inhibitors. Preliminary bioassay results reveal that these derivatives are promising Arabidopsis thaliana HPPD (AtHPPD) inhibitors, in particular compounds I12 (Ki = 0.011 μM) and I23 (Ki = 0.012 μM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (Ki = 0.013 μM). Furthermore, the newly synthesized compounds show significant greenhouse herbicidal activities against tested weeds at dosages of 150 g ai/ha. In particular, II4 exhibited high herbicidal activity for pre-emergence treatment that was slightly better than that of mesotrione. In addition, compound II4 was safe for weed control in maize fields at a rate of 150 g ai/ha, and was identified as the most potent candidate for a novel HPPD inhibitor herbicide. The compounds described herein may provide useful guidance for the design of new HPPD inhibiting herbicides and their modification.
- Huang, Hao,Liu, Jian-Min,Shu, Lei,Wang, Man-Man,Yan, Yi-Le,Zhang, Da-Yong,Zhang, Jian-Qiu
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supporting information
p. 233 - 247
(2020/03/27)
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- Synthesis method of 2, 4-dichlorophenoxyacetic acid compound
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The invention relates to a synthesis method of a 2, 4-dichlorophenoxyacetic acid compound, and relates to the technical field of organic synthesis. The synthesis method of the 2, 4-dichlorophenoxyacetic acid compound is to solve the problems of many by-products existing in synthesis method of the 2, 4-dichlorophenoxyacetic acid compound in prior art, low conversion of phenol, incomplete conversion, environmental pollution resulted, the use of a large number of solvents, production of a large amount of wastewater, high cost, complex technology, high environmental risk, and being not conducive to industrial production. According to the synthesis method of the 2, 4-dichlorophenoxyacetic acid compound, in the synergistic action of anhydrous carbonate weak base and a catalyst, performing condensation of 2, 4-dichlorophenol with halogen acetate, and 2, 4-dichlorophenoxyacetic acid is obtained directly by hydrolysis and acidification. The process of the synthesis method of the 2, 4-dichlorophenoxyacetic acid compound is accomplished by condensation, hydrolysis and acid hydrolysis in one pot without any solvent and using anhydrous carbonate weak base to react with 2, 4-dichlorophenol can effectively inhibit the hydrolysis of chloroacetate, improve the condensation conversion, reduce the content of free phenol, keep a yield over 97% an active ingredient more than 98%, and free phenol content in 50-100 ppm.
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Paragraph 0052-0066
(2019/05/29)
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- Design and Synthesis of Novel 4-Hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one Derivatives for Use as Herbicides and Evaluation of Their Mode of Action
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In order to develop a novel herbicide containing the β-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.
- Lei, Kang,Li, Pan,Yang, Xue-Fang,Wang, Shi-Ben,Wang, Xue-Kun,Hua, Xue-Wen,Sun, Bin,Ji, Lu-Sha,Xu, Xiao-Hua
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p. 10489 - 10497
(2019/10/02)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: a) reacting haloacetate with 2,4-dichlorophenolate under the action of a composite catalyst of a halide salt and a phase-transfer catalyst so as to obtain 2,4-dichlorophenoxy acetate; and B) acidizing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the composite catalyst is added in the process of condensation of the haloacetate and 2,4-dichlorophenolate, so a reaction rate is increased, thorough reaction isrealized, and high yield and high product purity are obtained.
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Paragraph 0029; 0030; 0031; 0032; 0033; 0034; 0035-0046
(2018/09/28)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting 2,4-dichlorophenol with alkali to obtain 2,4-dichlorophenolate and reacting haloacetic acid with an alkali so as to obtain haloacetate; B) reacting the 2,4-dichlorophenolate with the haloacetate so as to obtain 2,4-dichlorophenoxyacetate; and C) mixing 2,4-dichlorophenoxyacetate with acid and carrying out piezocrystallization so as to obtain 2,4-dichlorophenoxyacetic acid, wherein pressurization pressure is 0.1 to 2.0 Mpa. According to the invention,the 2,4-dichlorophenolate and the haloacetate are separately prepared at first and then subjected to a reaction so as to produce the 2,4-dichlorophenoxyacetate; then the 2,4-dichlorophenoxyacetate ismixed with acid; and finally, piezocrystallization is carried out. With such a specific piezocrystallization manner, the prepared 2,4-dichlorophenoxyacetic acid is large in particle size and high inpurity and yield; and dust is not produced during drying and usage, so environment friendliness is achieved.
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Paragraph 0050-0053; 0056-0061
(2018/09/28)
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- Preparation method for 2,4-dichlorophenol, and preparation method for 2,4-dichlorophenolate
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The invention provides a preparation method for 2,4-dichlorophenol. The preparation method comprises the following steps: S) adding phenol, a promoter and sulfuryl chloride into an organic solvent andcarrying out chlorination under low temperature conditions to obtain 2,4-dichlorophenol, wherein the promoter is one or more selected from the group consisting of dimethyl sulfide, phenyl sulfide andisopropyl ether. Compared with the prior art, the preparation method provided by the invention has the advantage that selectivity is improved due to the reaction under low temperature conditions; andthe promoter is added at the same time to ensure a reaction rate.
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Paragraph 0046; 0047
(2018/09/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: a) reactinghalogenated acetate with 2,4-dichlorophenolate in the presence of a phase-transfer catalyst so as to obtain 2,4-dichlorophenoxyacetate; and b) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, oil-phase halogenated acetate reacts with 2,4-dichlorophenolate under the action of the phase-transfer catalyst to prepare 2,4-dichlorophenoxyacetate, and then 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid and corresponding alcohols. Under the action of the phase-transfer catalyst, few hydrolysis by-products are produced during a reaction, fast reaction speed and high conversion rate and yield are obtained, and the amount of produced waste water is low; so industrial application of the preparation method can be easily implemented.
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Paragraph 0047; 0049; 0050
(2018/09/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: a) reactinghalogenated acetate with an anhydrous 2,4-dichlorophenolate solid so as to obtain 2,4-dichlorophenoxyacetate; and b) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the anhydrous 2,4-dichlorophenolate solid reacts with halogenated acetate to prepare 2,4-dichlorophenoxyacetate, and then 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid and corresponding alcohols. The mass transfer effect of a solid-liquid reaction in the invention is good; few hydrolysis by-products are produced during the reaction; fast reaction speed and high conversion rate and yield are obtained; the amount of produced waste water is low; so industrial application of the preparation method can be easily implemented.
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Paragraph 0046; 0049
(2018/09/08)
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- Preparation method and posttreatment method of chlorophenoxycarboxylic acid herbicide
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The invention provides a preparation method of a chlorophenoxycarboxylic acid herbicide, wherein the preparation method includes the following steps: A) carrying out hydrolysis reaction of chlorophenoxycarboxylic ester in water with an acid compound as a catalyst, to obtain a chlorophenoxycarboxylic acid reaction liquid; and crystallizing the reaction liquid by a gradient cooling method comprisingthe steps successively: cooling to 95-80 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 80-70 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 70-60 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 60-50 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 50-30 DEG C, andcarrying out stirring heat preservation for 30-90 minutes; and cooling to 30 DEG C or less, to obtain chlorophenoxycarboxylic acid crystals and a mother liquor mixture. The method has no waste salt formation, and has the advantages of high conversion rate, recyclable utilization of the catalyst and water, recyclable alcohol, economy and environmental protection. The obtained chlorophenoxycarboxylic acid has the advantages of high purity, large particle size, high bulk density and easy transportation.
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Paragraph 0067; 0068
(2019/01/08)
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- A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprises the following steps: A) halogenated acetate with 2, 4 - dichlorophen salt reaction, to obtain 2, 4 - dichlorophenoxy ester; B) 2, 4 - dichlorophenoxy ester under the effects of catalyst hydrolysis reaction, to obtain 2, 4 - dichloro acid; said catalyst is selected from a polyether, a crown ether, quaternary ammonium salt, tertiary amine, [...], pyridine, titanate, inorganic acid, in organic acid one or more. The invention by halogenated acetate with 2, 4 - dichlorophen salt obtained by reaction of 2, 4 - dichlorophenoxy ester, and then in particular under the action of catalyst by hydrolysis reaction of the 2, 4 - dichloro acid. The invention specific reaction line combined with a specific catalyst such that the final preparation to obtain 2, 4 - dichlorophenoxyacetic acid purity and yield is relatively high, few by-products, the reaction route is simple, and is favorable for application. (by machine translation)
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Paragraph 0042; 0043; 0049
(2018/09/08)
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- A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprising: A) a halogenated acetic acid with the monoester should be halogenated acetate; phenol with alkali reaction to obtain the phenoxide; B) halogenated acetate and phenol salt reaction to obtain the phenoxyacetic acid ester; C) phenoxyacetic acid ester under the effects of catalyst chloride to obtain 2, 4 - dichlorophenoxy ester; said catalyst selected from iron trichloride, aluminum trichloride, boron trifluoride, five [...], trifluoromethyl sulfonate, aluminum oxide, ferric oxide, boron trioxide, niobium pentoxide, diphenyl ether, diphenyl sulfide, benzoin two sulfide, dimethyl sulfide and dimethyl sulfide in one or several of the D) 2, 4 - dichlorophenoxy ester hydrolysis to obtain 2, 4 - dichloro acid. This invention adopts the specific reaction routes and chlorinated using a specific catalyst, good reaction selectivity, few by-products, high yield. (by machine translation)
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Paragraph 0051; 0052
(2018/09/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting C2 or above-C2 alcohol with halogenated acetic acid soas to obtain halogenated acetate; B) reacting halogenated acetic acid with 2,4-dichlorophenolate so as to obtain 2,4-dichlorophenoxyacetate; and C) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, C2 or above-C2 alcohol reacts with halogenated acetic acid to obtain a halogenated acetate intermediate, the intermediate has good stability, few reaction by-products are produced, and high yield is realized; then the intermediate further reacts with 2,4-dichlorophenolate to obtain 2,4-dichlorophenoxyacetate; and finally, 2,4-dichlorophenoxyacetate is hydrolyzed to obtain 2,4-dichlorophenoxyacetic acid. Through a specific reaction route of the invention, the finally prepared 2,4-dichlorophenoxyacetic acid has high purity and yield, few by-products are produced, the reaction route is simple, and the application of the preparation method is facilitated.
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Paragraph 0046; 0047; 0055; 0061
(2018/09/08)
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- Preparation method of 2,4-dichlorophenoxyacetic acid and salt thereof
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The invention provides a preparation method of 2,4-dichlorophenoxyacetic acid and a salt thereof, wherein the preparation method includes the following steps: S1) carrying out a reaction of phenol andchloracetic ester under alkaline conditions to obtain phenoxyacetic ester; S2) carrying out selective chlorination reaction of the phenoxyacetic ester with a chlorinating agent under the action of acatalyst A and a catalyst B to obtain 2,4-dichlorophenoxyacetic ester, wherein the catalyst A is Lewis acid, and the catalyst B is C5-22 thioethers, thiazoles, isothiazoles and thiophenes or halogenated derivatives thereof; and S3) carrying out hydrolysis reaction of 2,4-dichlorophenoxyacetic ester under acidic conditions to obtain 2,4-dichlorophenoxyacetic acid; or after 2,4-dichlorophenoxyaceticester is obtained, carrying out an alkaline hydrolysis reaction with an alkaline compound to obtain 2,4-dichlorophenoxyacetate. The production and use of 2,4-dichlorophenol with unpleasant odor are avoided, the production of dioxins is eliminated, the yield of products is improved, and the output of three wastes is greatly reduced.
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Paragraph 0103; 0106
(2019/01/06)
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- A phenoxy carboxylic acid herbicide preparation method (by machine translation)
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The invention provides a phenoxy carboxylic acid herbicide preparation method, including: S1, will be [...], alkaline substance mixed with the chlorinated carboxylic acid ester, in the one-pot condensation reaction in anhydrous system, phenoxy carboxylic acid ester obtained; the ClR states the chloro- carboxylic acid ester of the formula is1 COOR, R1 Is C1 - 3 alkylene or alkylidene, R is C1 - 10 alkyl or C3 - 10 cycloalkyl; S2, the [...] ester in the 1st and 2nd catalyst under the action of a catalyst, with the chlorinating agent to carry out the selective chlorination of, get [...] ester; the Lewis acid catalyst is selected from 1st, 2nd catalyst is C5 - 22 of the thioether compound, thiazole compound, isothiazole compound or thiophene compound; S3, will the [...] ester to acid hydrolysis reaction, as shown in formula I phenoxy carboxylic acid herbicide, R3 Is H, Cl or CH3 . This invention can improve the quality of the products and the operating environment of production, three waste low. (by machine translation)
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- Preparation method of phenoxycarboxylic acid herbicide
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The invention provides a preparation method of a phenoxycarboxylic acid herbicide, wherein the preparation method includes the steps: S1, carrying out reaction of anhydrous phenol with an active metalto form phenoxide, and carrying out condensation reaction of the phenoxide with chlorocarboxylic ester to obtain phenoxycarboxylic ester, wherein the chlorocarboxylic ester has the general formula ofClR1COOR, R1 is C1-3 alkylene or alkylidene, and R is C1-10 alkyl or C3-10 of cycloalkyl; S2, carrying out selective chlorination of the phenoxycarboxylic ester with a chlorinating agent in the presence of a first catalyst and a second catalyst to obtain chlorobenzoxycarboxylic ester, wherein the first catalyst is selected from Lewis acid, and the second catalyst is C5-22 thioether, thiazole, isothiazole or thiophene compounds; and S3, carrying out acidolysis reaction of chlorobenzoxycarboxylic ester to obtain the phenoxycarboxylic acid herbicide represented by the formula I, wherein R3 is H,Cl or CH3. The preparation method can improve the product quality and the operation environment of the production site, and has low quantity of three wastes.
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- Preparation method of phenoxy carboxylic acid herbicide
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The invention provides a preparation method of a phenoxy carboxylic acid herbicide, comprising the following steps: S1, carrying out a condensation reaction between a phenolic compound and hydroxycarboxylic ester under the action of a catalyst so as to obtain phenoxycarboxylic ester, wherein the catalyst is one or more of protonic acid, solid acid and a supported catalyst; S2, carrying out 2- and/or 4- selecting chlorination reaction between phenoxycarboxylic ester and a chloridizing agent in the presence of a first catalyst and a second catalyst, so as to obtain chlorinated phenoxycarboxylicester, wherein the first catalyst is selected from Lewis acid, and the second catalyst is selected from a C5-C22 thioether compound, a C5-C22 thiazole compound, a C5-C22 isothiazole compound or a C5-C22 thiophene compound; and S3, carrying out an acidolysis reaction on chlorinated phenoxycarboxylic ester so as to obtain the phenoxy carboxylic acid herbicide. By the method, product quality and thelive environment of production can be improved, and ''three wastes (waste gas, waste water and industrial residue)'' are minimized.
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- Preparation method of phenoxycarboxylic acid herbicide
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The invention provides a preparation method of a phenoxycarboxylic acid herbicide, wherein the preparation method includes the steps: S1, carrying out condensation reaction of phenol or o-cresol withchlorocarboxylic ester under the action of an alkaline substance to obtain phenoxycarboxylic ester, wherein the chlorocarboxylic ester has the general formula of ClR1COOR, R1 is C1-3 alkylene or alkylidene, and R is C1-10 alkyl or C3-10 cycloalkyl; S2, carrying out selective chlorination of phenoxycarboxylic ester with a chlorinating agent under the action of a first catalyst and a second catalyst, to obtain chlorobenzoxycarboxylic ester, wherein the first catalyst is selected from Lewis acid, the second catalyst is C5-22 thioether compounds, thiazole compounds, isothiazole compounds or thiophene compounds; and S3, carrying out acidolysis reaction of chlorobenzoxycarboxylic ester, to obtain the phenoxycarboxylic acid herbicide represented by the formula I, wherein R3 is H, Cl or CH3. The preparation method can improve the product quality and the operation environment of a production site, and has low quantity of three wastes.
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: a) reacting haloacetic acid with 2,4-dichlorophenolate in a strong-polarity solvent so as to obtain 2,4-dichlorophenoxy acetate; and B) hydrolyzing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the strong-polarity solvent is utilized, so the mass transfer effect of the reaction is improved, reaction time is reduced, the reaction is more complete, and the conversion rate and yield of the reaction are greatly improved.
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Paragraph 0032; 0033; 0037; 0041
(2018/09/29)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: reacting phenol with a chloridizing agent under the action of a catalyst so as to obtain 2,4-dichlorophenol, wherein the catalyst is a composite catalyst composed of at least one metallic compound and at least one ether compound; reacting 2,4-dichlorophenol with analkaline compound so as to obtain 2,4-dichlorophenate; reacting haloacetic acid with an alkaline compound so as to obtain haloacetate; reacting the 2,4-dichlorophenate with the haloacetate so as to obtain 2,4-dichlorophenoxyacetate; and acidifying the 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the specific composite catalyst is added in the chlorination process of phenol, so the prepared 2,4-dichlorophenoxyacetic acid contains few by-products, has high purity and yield, and is friendly to environment.
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Paragraph 0053; 0055
(2018/09/29)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: a) reacting 2,4-dichlorophenol with alkali to obtain a 2,4-dichlorophenolate reaction solution, drying the 2,4-dichlorophenolate reaction solution so as to obtain a 2,4-dichlorophenolate solid, reacting haloacetic acid with an alkali so as to obtain a haloacetate reaction solution and carrying out drying so as to obtain a haloacetate solid; B) reacting the 2,4-dichlorophenolate solid with the haloacetate solid so as to obtain 2,4-dichlorophenoxyacetate; and C) acidifying the 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the 2,4-dichlorophenolate reaction solution and the haloacetate reaction solution are separately dried to remove water; and the 2,4-dichlorophenolate solid and the haloacetate solid are subjected to a reaction in a non-aqueous phase, so the reaction is more thorough, and the prepared 2,4-dichlorophenoxyacetic acid has high yield and purity.
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Paragraph 0053; 0054; 0056; 0058; 0060; 0062
(2018/09/29)
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- A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprises the following steps, first the polyol and a halogenated acetic acid to carry out the esterification reaction, to obtain halogenated acetate; then the above-mentioned step to obtain the halo acetate with 2, 4 - dichlorophen salt, to obtain 2, 4 - dichlorophenoxy ester; finally in the composite under the action of catalyst, obtained by the above-mentioned step 2, 4 - dichlorophenoxy ester hydrolytic reaction, to obtain 2, 4 - dichloro acid and polyol; the polyol C atoms is greater than or equal to 2 polyol. The invention adjusts the process route, from creative improvement on the basis of, the preparation method, the process is simple, mild condition, hydrolysis few by-products, the product has high purity, the conversion and yield higher, and intermediate halogenated acetate stable, suitable for large-scale industrial production. (by machine translation)
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Paragraph 0075; 0076
(2018/09/08)
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- Preparation method for 2,4-dichlorophenol, and preparation method for 2,4-dichlorophenolate
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The invention provides a preparation method for 2,4-dichlorophenol. The preparation method comprises the following steps: S1) mixing an initiator, phenol and a promoter in an organic solvent and carrying out chlorination under low temperature conditions to obtain the chlorination tail gas of phenol and a reaction solution, wherein the initiator is sulfuryl chloride, and the promoter is an ether compound; S2) mixing the chlorination tail gas of phenol with chlorine gas for a reaction to obtain sulfuryl chloride; and S3) mixing the sulfuryl chloride with the reaction solution and carrying out chlorination to obtain the chlorination tail gas of phenol and 2,4-dichlorophenol. Compared with the prior art, the invention has the following advantages: since chlorine gas is used as an initial chlorination raw material and continuously produces sulfuryl chloride through a reaction with sulfur dioxide in the chlorination tail gas of phenol, and then the sulfuryl chloride is continuously added into the reaction solution to obtain 2,4-dichlorophenol, so the preparation method has the advantages of high selectivity, low cost, high yield and simple flow due to adoption of continuous reaction andtail gas recycling flow; moreover, the reaction is carried out under low temperature conditions, so selectivity is improved; and the promoter is used, so a reaction rate is increased.
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Paragraph 0069; 0070
(2018/09/08)
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- Preparation method of phenoxycarboxylic acid substances
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The invention provides a preparation method of phenoxycarboxylic acid substances, wherein the preparation method includes the steps: S1) mixing phenol compounds represented by the formula (I) and halogenated fatty alcohols represented by the formula (II) with alkali metal carbonates in organic solvents, carrying out heating reaction to obtain phenoxy fatty alcohols; S2) carrying out reaction of the phenoxy fatty alcohols with oxidants to obtain phenoxy fatty acids; and S3) carrying out mixed reaction of the phenoxy fatty alcohols, a chlorination catalyst and a chlorinating agent to obtain thephenoxycarboxylic acid substances represented by the formula (III). Compared with the prior art, the phenoxy fatty alcohols are obtained with phenolic compounds as the starting raw material, and thenoxidized and chlorinated to obtain the phenoxycarboxylic acid compounds. The method does not need dehydration, is environmentally friendly, has no chlorophenol participation, cannot produce dioxins, solves the problem of large odor, and has high selectivity for directional chlorination. At the same time, the method does not need cumbersome enrichment devices. The whole process is simple, the investment of equipment is low, and the energy consumption is reduced.
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- A method for preparing 2, 4 - dichlorophenoxyacetic acid (by machine translation)
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The invention provides a 2, 4 - dichlorophenoxyacetic acid preparation method, comprises the following steps, first alcohol and a halogenated acetic acid after the reaction, to obtain halogenated acetate; the 2, 4 - dichlorophen after reaction with the alkali, to obtain 2, 4 - II [...]; then the above-mentioned step to obtain the halo acetate with 2, 4 - dichlorophen salt, to obtain 2, 4 - dichlorophenoxy ester; then obtained the above-mentioned step 2, 4 - dichlorophenoxy ester hydrolytic reaction, to obtain the 2, 4 - dichloro acid and alcohol; finally the above-mentioned step returns mellowly obtained is used in the aforesaid step, recycling; the alcohol is C atom number greater than or equal to 2 alcohol. The invention adjusts the process route, from the improved on the basis of, the reaction process is cleaning, of the small amount of waste water, hydrolysis few by-products, high purity of the product, the conversion and yield higher; and process raw materials can be recycled, is suitable for large-scale industrial production. (by machine translation)
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Paragraph 0082; 0085-0087; 0090; 0091
(2018/09/08)
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- Preparation method and production system for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: a) reacting 2,4-dichlorophenol with an alkali to obtain 2,4-dichlorophenolate and reacting haloacetic acid with an alkali so as to obtain haloacetate; B) reacting the 2,4-dichlorophenolate with the haloacetate so as to obtain 2,4-dichlorophenoxyacetate; and C) mixing the 2,4-dichlorophenoxyacetate with acid and carrying out crystallization in a tubular crystallizer so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, the 2,4-dichlorophenolate and the haloacetate are separately prepared at first and then subjected to a reaction so as to produce the 2,4-dichlorophenoxyacetate; then the 2,4-dichlorophenoxyacetate is mixed with acid; and finally, crystallization in the tubular crystallizer is carried out. With such a specific continuous crystallization manner, the prepared 2,4-dichlorophenoxyacetic acid is large in particle size and high in purity and yield; and dust is not produced during drying and usage, so environment friendliness is achieved.
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Paragraph 0079-0080; 0082-0088
(2018/09/28)
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- Preparation method of chlorophenoxycarboxylic acid herbicide
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The invention provides a preparation method of a chlorophenoxycarboxylic acid herbicide, wherein the preparation method includes the following steps: A) carrying out hydrolysis reaction of chlorophenoxycarboxylic ester under the action of hydrochloric acid, wherein the reaction system contains a surfactant; B) after the reaction is finished, dividing the system into an oil phase and a water phase,and cooling and crystallizing the oil phase, to obtain chlorophenoxycarboxylic acid. Hydrochloric acid is chosen as an acid catalyst and is used in combination with the surfactant; in the reaction process, the raw material and the catalyst are fully contacted, the reaction rate is increased, the reaction time is shortened, and the reaction is more thorough; after the reaction is finished, the oilphase and the water phase are stratified to facilitate the separation of the product and the catalyst. Excess hydrochloric acid can be evaporated and recycled, water-washing water can be recycled, nowaste salt or waste water exists, the energy consumption is low, and the preparation method is economic and environmentally friendly.
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Paragraph 0036; 0037; 0040-0049
(2019/01/08)
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- Preparation method of chlorophenoxycarboxylic acid herbicide
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The invention provides a preparation method of a chlorophenoxycarboxylic acid herbicide, wherein the preparation method includes the following steps: A) carrying out hydrolysis reaction of chlorophenoxycarboxylic ester under the catalytic action of hydrochloric acid and metal chloride; B) after the reaction is finished, dividing the system into an oil phase and a water phase, and cooling and crystallizing the oil phase, to obtain chlorophenoxycarboxylic acid. Hydrochloric acid and metal chloride are used as a compound catalyst; in the reaction process, the raw material and the catalyst are fully contacted, the reaction rate is increased, the reaction time is shortened, and the reaction is more thorough; after the reaction is finished, the oil phase and the water phase are stratified to facilitate the separation of the product and the catalyst. Excess hydrochloric acid can be evaporated and recycled, water-washing water can be recycled, no waste salt or waste water exists, the energy consumption is low, and the preparation method is economic and environmentally friendly.
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Paragraph 0048; 0049
(2019/01/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting halogenated acetic acid with alcohol so as to obtain halogenated acetate, and reacting phenol with alkali to obtain phenolate; B) reacting halogenated acetate with phenolate to obtain phenoxyacetate; C) hydrolyzing phenoxyacetate to obtain phenoxyaceticacid; and D) chlorinating phenoxyacetic acid under the action of a catalyst to obtain 2,4-dichlorophenoxyacetic acid, wherein the catalyst is one or more selected from the group consisting of ferric trichloride, aluminum trichloride, boron trifluoride, niobium pentachloride, trifluoromethanesulfonate, alumina, ferric oxide, boron trioxide, niobium pentoxide, diphenyl ether, diphenyl sulfide, diphenyl disulfide, dimethyl sulfide and dimethyl disulfide. According to the invention, phenolate reacts with halogenated acetate to obtain phenoxyacetate, then phenoxyacetate is hydrolyzed to obtain phenoxyacetic acid, and phenoxyacetic acid is chlorinated under the action of the specific catalyst so as to obtain 2,4-dichlorophenoxyacetic acid. The preparation method of the invention uses the specific catalyst, and has the advantages of good reaction selectivity, few by-products and high yield.
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Paragraph 0050; 0051; 0052; 0053; 0054; 0055
(2018/09/08)
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- A method for preparing chloro-benzene oxygen carboxylic acid (by machine translation)
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The invention provides a method for preparing carboxylic acid chloro-benzene oxygen, comprising the following steps: S1) phenoxy fatty alcohol in the catalyst B A and under the action of the catalyst, and the chlorinating agent to 2 bit and/or 4 bit selective chlorination reaction, to obtain chloro-benzene oxygen fatty alcohol; said catalyst A is Lewis acid; said catalyst B is C5 - 22 of the thioether, thiazole, isothiazole, thiophene or their halogenated derivatives; S2) [...] fatty alcohol and water, under the action of a catalyst, and an oxidizing agent for the selective catalytic oxidation reaction, get chloro-benzene oxygen carboxylic acid. The invention through the re-design of the process route, the catalyst and the chlorinating agent fine screening, effectively reduces the energy consumption, the selectivity of the dichloride to improve at the same time avoiding the losses of the active ingredient, the resulting chloro-benzene oxygen carboxylic acid content can be up to 98.5% or more, the total yield can be up to 99% or more. (by machine translation)
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Paragraph 0049; 0051-0053; 0055; 0056; 0058; 0077; 0079
(2019/01/08)
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- Preparation method of chlorophenoxycarboxylic acid substance
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The invention provides a preparation method of a chlorophenoxycarboxylic acid substance, wherein the preparation method includes the steps: S1) carrying out mixed reaction of phenoxy fatty alcohol represented by the formula (I), an oxidant, an oxidation catalyst and an alkaline substance, and filtering to obtain a reaction liquid; and S2) carrying out mixed reaction of the reaction liquid, a catalyst A, a catalyst B and a chlorinating agent to obtain the chlorophenoxycarboxylic acid substance represented by the formula (II). Compared with the prior art, phenoxy fatty alcohol is firstly directly oxidized in the oxidation catalyst and the alkaline environment to obtain phenoxy fatty acid salt, and then the phenoxy fatty acid salt is subjected to catalytic chlorination to obtain the chlorophenoxycarboxylic acid substance. The preparation method has the advantages of no need of cumbersome concentration device, simple process, no need of high temperature, low energy consumption, high selectivity, low consumption of raw materials and low content of waste water and waste salt.
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Paragraph 0038-0044
(2019/01/08)
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- Preparation method for 2,4-dichlorophenoxyacetic acid
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The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting a divalent salt of glycolic acid as shown in a formula(I) with 1,2,4-trichlorobenzene under the action of a catalyst so as to produce 2,4-dichlorophenoxyacetate as shown in a formula (II); and B) acidizing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, 1,2,4-trichlorobenzene is creatively used for replacing phenol and chlorophenol and subjected to a condensation reaction with glycolate so as toproduce 2,4-dichlorophenoxyacetate, and hydrolysis is carried out so as to prepare 2,4-dichlorophenoxyacetic acid; so such a technical scheme effectively avoids the usage of phenol or chlorophenol, overcomes the problems of peculiar smell of an operation place and production of waste gas, waste water and industrial residues, greatly improves the operation environment of the operation place and produces good environmental protection benefits, and the reaction has high yield and purity.
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Paragraph 0037; 0038; 0044; 0045
(2018/09/28)
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- Method for preparing 2,4-dichlorphenoxyacetic acid
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The invention provides a method for preparing 2,4-dichlorphenoxyacetic acid. The method comprises the step S1 of causing haloacetic acid and alkali metal alkoxide react in an alcohol solvent toobtain halogenated acetate, the step S2 of causing the halogenated acetate and phenoxide to react in the alcohol solvent to obtain phenoxyacetic acid salt, the step S3 of causing the phenoxyacetic acid salt to undergo chlorination in the alcohol solvent, and obtaining 2,4-dichlorobenzene acetate, and the step S4 of acidizing 2,4-dichlorobenzene acetate to obtain 2,4-dichlorphenoxyacetic acid. Compared with the prior art, the method enables chlorination to be performed in an anhydrous system, reaction selectivity is good, by-products are fewer, the yield is high, the 2,4-dichlorphenoxyacetic acid can be obtained after acidification, and the 2,4-dichlorphenoxyacetic acid is simple to prepare.
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Paragraph 0033-0052
(2017/07/21)
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- Preparation method of 2,4-dichlorphenoxyacetic acid
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The invention discloses a preparation method of 2,4-dichlorphenoxyacetic acid. The preparation method specifically comprises the following steps: adding methyl 2,4-dichlorophenoxyacetate to water, adding a solid acid catalyst, stirring and heating, carrying out refluxing for 2 to 8 hours, steaming out methanol generated by a reaction, cooling to room temperature after the reaction is finished, carrying out pumping filtration, washing and drying to obtain 2,4-dichlorphenoxyacetic acid. According to the invention, an esterolysis method used for preparing 2,4-dichlorphenoxyacetic acid refers to catalytic hydrolysis which uses the solid acid catalyst and is complete in hydrolysis, thereby not producing waste salt and waste water, being convenient to operate and capable of obtaining the high-purity product in a high yield.
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Paragraph 0025; 0026; 0027; 0028; 0029; 0030: 0031-0043
(2017/02/09)
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- Novel synthesis process of 2,4-dichlorphenoxyacetic acid
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The invention discloses a novel synthesis process of 2,4-dichlorphenoxyacetic acid. The technique is characterized by comprising the following steps: (1) in the existence of a water-carrying agent, carrying out reflux water-carrying reaction on 2,4-dichlorophenol and an inorganic alkali water solution to obtain a 2,4-dichlorophenate anhydrous system; (2) after the reaction solution in the step (1) is cooled, dropwisely adding methyl chloroacetate, and carrying out reflux reaction to obtain methyl 2,4-dichlorphenoxyacetate; (3) separating, purifying and desolventizing; and (4) hydrolyzing the methyl 2,4-dichlorphenoxyacetate under the action of a solid acid catalyst to prepare the 2,4-dichlorphenoxyacetic acid. The method solves the problem of generation of waste salts and wastewater in the traditional technique for preparing 2,4-dichlorphenoxyacetic acid, does not have the problem of hydrolysis of chloroacetic acid, and has the advantages of high yield, favorable purity and low cost.
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Paragraph 0082-0096; 0098-0101
(2017/02/09)
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- Method for synthesizing chlorophenoxyacetic acid or chlorophenol
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The invention relates to a method for synthesizing chlorophenoxyacetic acid or chlorophenol. The method comprises: (1) heating and melting phenol, methylphenol, phenoxyacetic acid or 2-methylphenoxyacetic acid or adding a solvent to dissolve phenol, methylphenol, phenoxyacetic acid or 2-methylphenoxyacetic acid; and (2) heating the material obtained in the step (1) to achieve a reaction temperature, introducing chlorine gas, adding hydrogen peroxide when the introduced chlorine gas accounts 2-50% of the total introducing amount, and oxidizing hydrogen chloride to generate chlorine gas so as to be recycled. According to the present invention, with the synthesis method, the amount of the by-produced hydrogen chloride is substantially reduced, and the chlorination selectivity of the late-stage reaction is improved.
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Paragraph 0036; 0037; 0051; 0052
(2018/04/02)
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- Synthesis and Biological Activity of Ethyl 4-Alkyl-2-(2-(substituted phenoxy)acetamido)thiazole-5-carboxylate
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(Chemical Equation Presented) A series of novel ethyl 4-(methyl or trifluoromethyl)-2-(2-(substituted phenoxy)acetamido)thiazole-5-carboxylates 7a, 7b, 7c, 7d, 7e and 8f, 8g, 8h, 8i, 8j, 8k, 8l, 8m, 8n, 8o, 8p, 8q, 8r were synthesized, and their structures were confirmed by IR, 1H-NMR, MS spectra and elemental analysis. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal activities. Compared with the fluorine free compounds 7a, 7b, and 7e, the compounds bearing fluorine 8g, 8j, and 8q showed higher herbicidal activities with 70-100% inhibition against Capsella bursa-pastoris, Amaranthus restroflexus, and Eclipta prostrata at the dosage of 150 g/ha, which indicated that the trifluoromethyl on the thiazole ring was beneficial for the herbicidal activity. Furthermore, compounds 8f, 8g, 8h, 8i, 8j, 8k, 8l, 8m, 8n, 8o, 8p, 8q, 8r were tested for fungicidal activity against Pseudoperonospora cubensis at 500 μg/mL. Compounds 8f and 8q showed the best fungicidal activity with more than 80% inhibition.
- Mo, Wenyan,Shi, Yanxia,He, Junbo,Li, Baoju,Peng, Hao,He, Hongwu
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p. 183 - 187
(2016/02/10)
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- Continuous to produce herbicide 2,4-dichlorophenoxy acetic acid method
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The invention discloses a method for continuously producing herbicide 2,4-dichlorophenoxyacetic acid. According to the method, phenol and chlorine gas are used as raw materials; a continuous chlorination reaction is conducted through a micro-channel reactor to prepare 2,4-dichlorophenol, a condensation reaction is conducted through a tandem condensation reaction kettle to prepare 2,4-dichlorphenoxyacetic acid sodium salt, and then a continuous acidification reaction is conducted through a tandem acidification reaction kettle to prepare the 2,4-dichlorphenoxyacetic acid. Since continuous operation is realized in all the three reactions, the technological process is efficient, environmentally friendly, sustainable and suitable for industrial production; the method has the advantages that energy is saved, consumption is lowered, and emission of pollutants is reduced, and therefore safe and continuous industrial production is achieved.
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Paragraph 0019; 0030; 0031
(2017/03/14)
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- An Efficient One-Pot Synthesis of 2-(Aryloxyacetyl)cyclohexane-1,3-diones as Herbicidal 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors
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4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) is an important target for new bleaching herbicides discovery. As a continuous work to discover novel crop selective HPPD inhibitor, a series of 2-(aryloxyacetyl)cyclohexane-1,3-diones were rationally designed and synthesized by an efficient one-pot procedure using N,N′-carbonyldiimidazole (CDI), triethylamine, and acetone cyanohydrin in CH2Cl2. A total of 58 triketone compounds were synthesized in good to excellent yields. Some of the triketones displayed potent in vitro Arabidopsis thaliana HPPD (AtHPPD) inhibitory activity. 2-(2-((1-Bromonaphthalen-2-yl)oxy)acetyl)-3-hydroxycyclohex-2-en-1-one, II-13, displayed high, broad-spectrum, and postemergent herbicidal activity at the dosage of 37.5-150 g ai/ha, nearly as potent as mesotrione against some weeds. Furthermore, II-13 showed good crop safety against maize and canola at the rate of 150 g ai/ha, indicating that II-13 might have potential as a herbicide for weed control in maize and canola fields. II-13 is the first HPPD inhibitor showing good crop safety toward canola.
- Wang, Da-Wei,Lin, Hong-Yan,He, Bo,Wu, Feng-Xu,Chen, Tao,Chen, Qiong,Yang, Wen-Chao,Yang, Guang-Fu
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p. 8986 - 8993
(2016/12/09)
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- A process for preparing 2,4-dichlorophenoxy acetic acid method
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The invention discloses a method for preparing 2,4-dichlorophenoxyacetic acid. The method comprises the following specific steps of adding chloroacetic acid into a sodium hydroxide solution, stirring, adding phenol and adjusting the pH to 11 with sodium bicarbonate; heating for 40 minutes at 100 DEG C; adding hydrochloric acid to adjust the pH value to 4; finally cooling in an ice-water bath to obtain a solid, washing the obtained solid and drying to obtain phenoxy acetic acid; adding the phenoxy acetic acid into a mixed solution of acetic acid and water, adding iron phthalocyanine and stirring; introducing chlorine to carry out chlorination reaction; reacting for 35-50 minutes until the chlorination reaction is completed to obtain a reaction product; cooling the reaction product and filtering to obtain a solid substance; and finally cooling the solid substance to obtain the finished product 2,4-dichlorophenoxyacetic acid, wherein the molar amount of iron phthalocyanine is 0.1% of phenoxy acetic acid. By the method, the product has the advantages of high quality, high yield and high purity; the preparation process is simple and stable, low in industrial cost and environmental friendly.
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Paragraph 0020; 0021; 0022-0031
(2018/02/04)
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- 2,4-dichlorophenoxyacetic acid preparation method
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The invention provides a 2,4-dichlorophenoxyacetic acid preparation method including the following steps: A) providing phenoxyacetic acid; B) mixing hydrochloric acid, an oxidizing agent and the phenoxyacetic acid of the step A), carrying out a chlorination reaction in the presence of a chlorination catalyst, to obtain 2,4-dichlorophenoxyacetic acid, wherein the molar ratio of the phenoxyacetic acid to the hydrochloric acid to the oxidizing agent is 1 to (2-200) to (2-200), and the molar ratio of the hydrochloric acid to the oxidizing agent is 1 to (0.1-10). The 2,4-dichlorophenoxyacetic acid preparation method provided by the invention only needs one-step chlorination reaction, and then the 2,4-dichlorophenoxyacetic acid can be obtained; while the purity and yield of the 2,4-dichlorophenoxyacetic acid are ensured, the production process of the 2,4-dichlorophenoxyacetic acid is simplified. Moreover, the preparation method provided by the invention has no 'three wastes' emissions and achieves greenization of synthesis of the product.
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Paragraph 0100-0101
(2017/03/14)
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- Synthesis and biological activity of 1-(Substituted phenoxyacetoxy)- 1-(pyridin-2-yl or thien-2-yl)methylphosphonates
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A series of novel O,O-dimethyl 1-(substituted phenoxyacetoxy)-1-(pyridin-2-yl or thien-2-yl)methylphosphonates 6a-n and 7a-d were synthesized. Their structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal and fungicidal activities. For example, the title compounds 6a, 6c, 6l, 6m, and 7d possess 90-100% inhibition against most of the tested plants at the dosage of 1500 g ai/ha, whereas the title compounds 6b, 6g-h and 6n possess 92-100% inhibition against Fusarium oxysporum, Phyricularia grisea, Botrytis cinereapers, Gibberella zeae, Sclerotinia sclerotiorum, and Cercospora beticola at the concentration of 50mg/L.
- Wang, Tao,Wang, Wei,Peng, Hao,He, Hongwu
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p. 173 - 179
(2015/01/30)
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- Radical decarboxylative fluorination of aryloxyacetic acids using N-fluorobenzenesulfonimide and a photosensitizer
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Fluorinated methoxy arenes are emerging as important motifs in both agrochemicals and pharmaceuticals. A novel technique for the synthesis of monofluoromethoxy arenes through the direct fluorodecarboxylation of carboxylic acids was developed that uses photosensitizers and N-fluorobenzenesulfonimide (NFSI). Utilization of the oxidatively mild fluorine transfer agent NFSI enabled the synthesis of fluoromethyl ethers that were previously inaccessible with decarboxylative fluorinations performed with Selectfluor. Mechanistic studies are consistent with the photosensitizer effecting oxidation of the aryloxyacetic acid.
- Leung, Joe C. T.,Sammis, Glenn M.
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supporting information
p. 2197 - 2204
(2015/04/14)
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- Effective catalytic hydrodechlorination of chlorophenoxyacetic acids over Pd/graphitic carbon nitride
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Catalytic hydrodechlorination (HDC) of chlorophenoxyacetic acids was performed over Pd/graphitic carbon nitride (Pd/g-C3N4) catalysts in the present work. A series of Pd/g-C3N4 catalysts were prepared by a deposition-precipitation method, and characterized by X-ray diffraction (XRD), N2 adsorption-desorption, transmission electron microscopy (TEM), CO chemisorption and X-ray photoelectron spectroscopy (XPS). The Pd/g-C3N4 catalysts showed excellent activity to convert dichlorophenoxyacetic acid (2,4-D) into phenoxyacetic acid (PA) and the catalytic activity was correlated with the ratio of Pd2+/(Pd0 + Pd2+) and Pd particle size. In addition, HDC of 2,4-D over Pd/g-C3N4 catalyst followed the Langmuir-Hinshelwood model, indicating an adsorption-controlled mechanism. Other chlorophenoxyacetic acids, such as 2-chlorophenoxyacetic acid (2-CPA), 4-chlorophenoxyacetic acid (4-CPA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) could also be completely dechlorinated to PA over Pd/g-C3N4 catalysts.
- Jiang, Fang,Tan, Wenhui,Chen, Huan,Tan, Ling,Liu, Jingliang
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p. 51841 - 51851
(2015/06/25)
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- Design, synthesis and molecular docking of amide and urea derivatives as Escherichia coli PDHc-E1 inhibitors
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By targeting the ThDP binding site of Escherichia coli PDHc-E1, two new 'open-chain' classes of E. coli PDHc-E1 inhibitors, amide and urea derivatives, were designed, synthesized, and evaluated. The amide derivatives of compound 6d, with 4-NO2 in the benzene ring, showed the most potent inhibition of E. coli PDHc-E1. The urea derivatives displayed more potent inhibitory activity than the corresponding amide derivatives with the same substituent. Molecular docking studies confirmed that the urea derivatives have more potency due to the two hydrogen bonds formed by two NH of urea with Glu522. The docking results also indicate it might help us to design more efficient PDHc-E1 inhibitors that could interact with Glu522.
- He, Jun-Bo,Ren, Yan-Liang,Sun, Qiu-Shuang,You, Ge-Yun,Zhang, Li,Zou, Peng,Feng, Ling-Ling,Wan, Jian,He, Hong-Wu
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p. 3180 - 3186
(2014/06/09)
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- Synthesis, Structure, and Properties of the 2-[5-(Aryloxyacetyl)-Amino-1,3,4-Thiadiazol-2-Ylthio] Propionate Derivatives
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A series of novel 2-[5-(aryloxyacetyl)-amino-1,3,4-thiadiazol-2-ylthio] propionate derivatives were synthesized in high yield, and their structures were characterized by IR, 1H NMR, 13C NMR, and elemental analysis, coupled with one selected single-crystal X-ray structure determination. The herbicidal activities of target compounds were assessed. The preliminary bioassay results showed that some compounds exhibited moderate to strong herbicidal symptoms in preemergence and postemergence tests. At 150 g/ha, S. tritici. show tolerance, while E. crus-galli L., E. Dahuricus, A. retroflexus, and C. glaucum L. were killed or severely injured. The activity of some compounds was comparable to the commercial herbicide 2,4-D. A suitable electron-withdrawing substituent at the 2-and/or 4-position of the phenyl ring was essential for high herbicidal activity. Moreover, the antifungal activities of the compounds have also been studied. The compounds were found to possess broad-spectrum antifungal activity.
- Hu, Bing,Zhai, Yue-Yuan,Zhang, Ling,Zhang, You-Ming,Wei, Tai-Bao
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p. 1337 - 1345
(2015/10/29)
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