1713-12-8Relevant articles and documents
Preparation method of phenoxy carboxylic acid herbicide
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, (2019/01/08)
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.
Preparation method of chlorophenoxycarboxylic ester
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Paragraph 0103; 0105; 0109; 0111, (2019/01/08)
The invention provides a preparation method of chlorophenoxycarboxylic ester, 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, the catalyst B has the following structural formula of R1'-S-R2', and the phenoxycarboxylic ester has any structure represented by the formulas I-IV; and S2) carrying out transesterification reaction of chlorophenoxycarboxylic ester and alcohol under the action of a catalyst to obtain long-chain chlorophenoxycarboxylic ester, wherein the alcohol has the molecular formula of R2OH, and R2 is C4-20 alkyl or cycloalkyl. The method improves the yield and purity of chlorophenoxycarboxylic ester by redesigning of the process route and fine screening of the catalysts and the chlorinating agent. The content ofthe obtained chlorophenoxycarboxylic ester can reach 98.5% or more and the yield can reach 98.5% or more.
Preparation method of chlorophenoxycarboxylic ester
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Paragraph 0092; 0094, (2019/01/08)
The invention provides a preparation method of chlorophenoxycarboxylic ester, 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, the catalyst B is C5-22 thiazoles, isothiazoles and thiophenes or halogenated derivatives thereof, and the phenoxycarboxylic ester has any structure represented by the formulas I-IV; and S2) carrying out transesterification reaction of chlorophenoxycarboxylic ester and alcohol under the action of a catalyst to obtain long-chain chlorophenoxycarboxylic ester, wherein the alcohol has the molecular formula ofR2OH, and R2 is C4-20 alkyl or cycloalkyl. The method improves the yield and purity of chlorophenoxycarboxylic ester by redesigning of the process route and fine screening of the catalysts and the chlorinating agent. The content of the obtained chlorophenoxycarboxylic ester can reach 98.5% or more and the yield can reach 98.5% or more.
