1917-96-0Relevant articles and documents
Preparation method of chlorophenoxyacetic ester
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, (2019/01/08)
The invention provides a preparation method of chlorophenoxyacetic ester, wherein the preparation method comprises the following steps: A) carrying out reaction of glycolic acid and alcohol in tolueneto obtain glycolic ester; B) carrying out reaction of glycolic ester and metal alkoxide to obtain a metal salt of glycolic ester; and C) carrying out reaction of the metal salt of glycolic ester andchlorobenzene to obtain the chlorophenoxyacetic ester. The chlorophenoxyacetic ester is synthesized by condensation of chlorobenzene with the metal salt of glycolic ester, the use of chlorophenol withunpleasant odor is effectively avoided, the production of highly toxic dioxins is eliminated, and the product quality and the operating environment of the production site are greatly improved. Motherliquor containing effective ingredients cannot be produced, so the loss of effective ingredients is effectively avoided and the yield of the product is improved.
Preparation method of 2,4-dichlorophenoxyacetic acid and salt thereof
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Paragraph 0119; 0121, (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.