25184-73-0

Usage

InChI:InChI=1/C13H16Cl2O3/c1-3-4-7-17-13(16)9(2)18-12-6-5-10(14)8-11(12)15/h5-6,8-9H,3-4,7H2,1-2H3

Upstream product

• 58048-37-6 2-(2,4-dichloro-phenoxy)-propionyl chloride 
• 71-36-3 butan-1-ol 
• 120-36-5 2-(2,4-dichlorophenoxy)propionic acid 

Relevant academic research and scientific papers

Preparation method of chlorophenoxycarboxylic ester

The invention provides a preparation method of chlorophenoxycarboxylic ester, wherein the preparation method includes the following steps: carrying out 2-site and/or 4-site selective chlorination reaction 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 is C5-22 thiazoles, isothiazoles and thiophenes or halogenated derivatives thereof. The method effectively improves the chlorination selectivity and avoids loss of effective ingredients 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 99% or more.

Preparation method of chlorophenoxycarboxylic ester

The invention provides a preparation method of chlorophenoxycarboxylic ester, wherein the preparation method includes the following steps: carrying out 2-site and/or 4-site selective chlorination reaction 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'. The method effectively improves the chlorination selectivity and avoids loss of effective ingredients 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 99% or more.

A [...] ester preparation method (by machine translation)

The invention provides a method for preparing [...] ester, including: the phenoxy carboxylic acid ester compounds, supported Lewis acid catalyst, sulfur-containing polymer mixed with the chlorinating agent, the selective chlorination reaction, to obtain [...] ester. Compared with the prior art, this invention uses benzene oxygen suo acid ester compound as a raw material obtained by the selective chlorination of [...] ester, simple preparation method, to avoid having the bad smell of the Fe0 production and use, thereby fundamentally preventing the substance to the dioxin generation; at the same time supported Lewis acid and sulfur-containing polymer common as catalyst, through the two cooperative positioning function, the selectivity of the dichloride to improve, and the two can through the filter recovery and re-use, the use of the recycling of the catalyst; furthermore the invention avoids the losses of the active ingredient, the extraction rate of the product, reduces energy consumption, prevent high COD, the generation of high salt waste water, three waste output has been largely reduced. (by machine translation)

Dynamic enzymatic resolution of thioesters

A detailed investigation of several issues related to the enzymatic resolution of thioesters under conditions of continuous racemization of substrate was conducted. The kinetic acidity of the α-protons of a series of α-substituted propionate thioesters was studied. It was found that the rate of α-proton exchange could be enhanced as much as 20-fold by variation of the thiol moiety, increasing the range of compounds to which enzymatic dynamic resolution may be applied. The relative rates of hydrolysis of ethyl butyrate and ethyl thiobutyrate by several enzymes commonly used in enzymatic resolution were determined. All of the enzymes studied exhibited similar rates of thioester and oxoester hydrolysis except for the esterase from pig liver, which showed very low activity in thioester hydrolysis. Dynamic resolution of the propargyl and trifluoroethyl thioesters of α- phenylpropionate was conducted using subtilisin Carlsberg as a catalyst. These examples demonstrated that enzymatic dynamic resolution can be applied even when the rate of α-proton exchange and the enantioselectivity of the enzyme are fairly low. A dynamic enzymatic transesterification procedure was demonstrated in the resolution of the trifluoroethyl thioester of α-(2,4- dichlorophenoxy)propionate, and product was obtained in 93% ee. This work helps expand and define the scope of enzymatic dynamic resolution of thioesters.