- Method for preparing (R)-(+)-2-(4-hydroxyphenoxy) methyl propionate
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The invention provides a method for preparing (R)-(+)-2-(4-hydroxyphenoxy) methyl propionate, and belongs to the technical field of preparation of pesticide intermediates. The method for preparing (R)-(+)-2-(4-hydroxyphenoxy) methyl propionate comprises the following steps: mixing halogenated methyl propionate, hydroquinone, an alkaline reagent and a polar aprotic solvent, and carrying out condensation reaction to obtain (R)-(+)-2-(4-hydroxyphenoxy) methyl propionate, wherein the halogenated methyl propionate is (S)-(-)-methyl-2-chloropropionate), (S)-(-)-methyl-2-bromopropionate or (S)-(-)-methyl-2-iodopropionate. According to the method, hydroquinone and halogenated methyl propionate are taken as raw materials, (R)-(+)-2-(4-hydroxyphenoxy) methyl propionate (MAQ) is synthesized in a polar aprotic solvent system through a one-step method, the process is simple, environment friendliness is achieved, the product quality is good, and the yield is high.
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Paragraph 0049-0050
(2021/04/26)
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- Method for synthesizing herbicide clodinafop-propargyl key intermediate
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The invention discloses a method for synthesizing a herbicide clodinafop-propargyl key intermediate. According to the method, methyl 2-chloropropionate and hydroquinone are used as starting raw materials, under the catalytic action of inorganic alkali, nucleophilic substitution reaction is conducted, and methyl (R,S)-2-(4-hydroxyphenoxy)propionate is obtained; the generated methyl (R,S)-2-(4-hydroxyphenoxy)propionate is subjected to resolution hydrolysis reaction under the action of aspergillus oryzae WZ007, and a methyl (R)-(+)-2-(4-hydroxyphenoxy)propionate product is obtained; the generatedproduct is subjected to hydrolysis reaction continuously to obtain a target product R(+)-2-(4-hydroxyphenoxy)propionic acid. The synthesis method is simple; in the synthesis process, thalli of the aspergillus oryzae WZ007 are used for catalyzing selective hydrolysis of a methyl (R,S)-2-(4-hydroxyphenoxy)propionate substrate, thus the R-configuration ester and the S-configuration acid are obtained, the purpose of resolution is achieved, moreover, the raw materials of the method are cheap, the production cost is low, and the economic performance is good, so that the method has good applicationprospects.
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- Preparation method of R-(+)-2-[4-(hydroxyphenoxy) propionate
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The invention discloses a preparation method of a herbicide intermediate R-(+)-2-[4-(hydroxyphenoxy) propionate by using a novel solid acid catalyst. The method improves the traditional esterification process, reduces the discharge of wastewater, and plays great improvement role in preventing the inversion of configuration of a chiral product.
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Paragraph 0029; 0030; 0031; 0032; 0033; 0034
(2017/06/02)
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- Resolution of (R, S)-ethyl-2-(4-hydroxyphenoxy) propanoate using lyophilized mycelium of Aspergillus oryzae WZ007
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The mycelium of Aspergillus oryzae WZ007 was successfully developed to kinetic resolution of (R, S)-ethyl-2-(4-hydroxyphenoxy) propanoate ((R, S)-EHPP) for production of (R)-ethyl-2-(4-hydroxyphenoxy) propanoate ((R)-EHPP). The key biocatalytic process parameters (pH, temperature, rotation speed and substrate concentration) were optimized. Under the optimum conditions, the optical purity of (R)-EHPP was improved up to >99% when the conversion was above 49%. A. oryzae WZ007 whole-cell lipase exhibited high reaction capacity, enantioselectivity and good reusability. The tolerable substrate concentration was 0.5 mol/L, and dry mycelium of A. oryzae WZ007 maintains over 80% of its initial activity after eight repeating cycles. Therefore the enzymatic preparation of (R)-EHPP route was suitable for industrial application.
- Zheng, Jian-Yong,Wu, Jia-Yu,Zhang, Yin-Jun,Wang, Zhao
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- Preparation of mixtures of (R)- and (S)-2-(4-alkanoylphenoxy)- or (R)- and (S)-2-(4-aroylphenoxy)propionic esters
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A mixture of (R)- and (S)-2-(4-alkanoylphenoxy)- or (R)- and (S)-2-(4-aroylphenoxy)propionic esters I STR1 with an enantiomeric excess of at least 90% is prepared by reacting a mixture of (R) and (S) enantiomer of a 2-phenoxypropionic ester II STR2 in which the appropriate (R) or (S) isomer is present in excess, with a carboxylic acid derivative of the formula III (X=OH, halogen, R1 COO or sulfonyloxy) in the presence of a Friedel-Crafts catalyst. The (R)- or (S)-2-(4-alkanoylphenoxy)propionic esters and (R)- or (S)-2-(4-hydroxyphenoxy)propionic esters are used for preparing crop protection agents and drugs.
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- Liquid crystal material
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A compound having ferroelectric liquid crystal properties of the formula: STR1 wherein A is the residue of a liquid crystal material or a liquid crystal compatible material; X is O or S; n is 0 or 1; Y is any inert group which does not cause the melting point of the compound of Formula I to exceed 200° C.; R1 is selected from H, C1-4 -alkyl and halogen; and R2 is C1-4 -alkyl or halogen; provided that R1 and R2 are different. In a suitable environment the compound is capable of alignment in two metastable states and is therefore suitable for use in multiplex-addressed, liquid crystal devices, such as flat bed large area screens and displays.
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