2008-39-1Relevant articles and documents
Preparation method of chlorophenoxycarboxamide salt
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, (2019/01/08)
The invention provides a preparation method of chlorophenoxycarboxamide salt, wherein the preparation method includes the following steps: S1) carrying out 2-site and/or 4-site selective chlorinationreaction of phenoxycarboxylic ester with a chlorinating agent under the action of a catalyst A and a catalyst B to obtain chlorophenoxycarboxylic ester, wherein the catalyst A is Lewis acid, and the catalyst B has the following structural formula of R1'-S-R2'; and S2) carrying out ammonolysis reaction of chlorophenoxycarboxylic ester and amine to obtain chlorophenoxycarboxamide salt. By redesigning of the process route and fine screening of the catalysts and the chlorinating agent, the method reduces energy consumption, improves chlorination selectivity and avoids loss of effective components.The yield of the obtained chlorophenoxycarboxamide salt can reach 98.5% or more. At the same time, the production of high-salt wastewater is completely eradicated, the dust hazard caused by drying and use of chlorophenoxycarboxylic acid is avoided, energy is saved and equipment investment is reduced.
Preparation method of 2,4-dichlorophenoxyacetic acid and salt thereof
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Paragraph 0111; 0114, (2019/01/06)
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.
PROCESS FOR PREPARATION OF HERBICIDAL SALTS
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Page/Page column 10-11, (2011/12/04)
A process for the preparation of solid amine salts of aromatic substituted carboxylic acid herbicides by reaction of the aromatic substituted carboxylic acid herbicide with an amine comprising reacting the aromatic substituted carboxylic acid herbicide in an ether solvent with an amine to form the amine salt and collecting the amine salt of the aromatic substituted carboxylic acid herbicide as a precipitate from the ether solvent reaction mixture wherein the ether is a dialiphatic ether comprising at least one primary aliphatic group.
