- Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid
-
The invention provides a preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid, and belongs to the technical field of pesticide intermediate preparation. According to the method, phenol is used as a raw material, phenol and (S)-(-)-2-halogenated propionic acid react to synthesize R-(+)-2-phenoxypropionic acid, and (R)-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained after oxidation. According to the invention, the raw material phenol used in the method is low in price, the procedure operation is simple, use of hydroquinone as the raw material is avoided, and the problems of high raw material cost, difficult product purification, low yield, low product quality and need of recovery of the raw material hydroquinone caused by hydroquinone disubstituted impurities generated in the reaction when hydroquinone is used as the raw material for synthesis in the traditional method are solved; and results of the embodiment show that the yield of the (R)-(+)-2-(4-hydroxyphenoxy) propionic acid prepared by the method is greater than 85%, the liquid phase content is greater than or equal to 99.5%, the optical purity e.e is greater than 99.0%, and the product is high in yield and good in quality.
- -
-
Paragraph 0052; 0054-0055; 0057-0058; 0060-0061; 0063
(2021/05/19)
-
- Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid
-
The invention provides a preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid, and belongs to the technical field of pesticide intermediates. Phenol compounds (parachlorophenol, p-bromophenol, p-iodophenol or p-hydroxybenzenesulfonic acid) are adopted as raw materials and react with (S)-(-)-2-chloropropionic acid to synthesize R-(+)-2-(4-chlorophenoxy) propionic acid, and the (R)-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained after hydrogen hydrolysis. The raw material phenol compound used in the invention is low in price and simple in process operation; and the method avoids using hydroquinone as a raw material, and solves the problems of high raw material cost, difficult product purification and low product quality caused by hydroquinone disubstituted impurities generated in the reaction when hydroquinone is used as a raw material for synthesis in the traditional method.
- -
-
-
- Preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid
-
The invention relates to the technical field of organic synthesis, in particular to a preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid. The preparation method provided by the invention comprises the following steps that p-nitrophenol and (S)-(-)-2-chloropropionic acid are subjected to substitution reaction under an alkaline condition to obtain R-(+)-2-(4-nitrophenoxy) propionic acid; the R-(+)-2-(4-nitrophenoxy) propionic acid and H2 are subjected to a reduction reaction under the catalysis condition of a catalyst, and the R-(+)-2-(4-aminophenoxy) propionic acid is obtained; and the R-(+)-2-(4-aminophenoxy) propionic acid and sodium nitrite are subjected to a diazotization hydrolysis reaction under the acidic condition, and the R-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained. The preparation method is simple, easy to obtain and low in cost, and the prepared R-(+)-2-(4-hydroxyphenoxy) propionic acid is high in yield and high in purity.
- -
-
-
- Preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid
-
The invention provides a preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid. The preparation method comprises the following steps: under the protection of inert gas, p-nitrophenol is usedas a starting raw material, and p-nitrophenoxy propionic acid is prepared through an etherification reaction; the p-nitrophenoxy propionic acid is reduced by adopting palladium on carbon to prepare p-aminophenoxy propionic acid; the optically pure R-(+)-2-(4-hydroxyphenoxy) propionic acid is prepared by diazotization and hydrolysis reaction of p-aminophenoxy propionic acid. The average yield of the preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid is not lower than 85%, and the product purity is 99.5% or above.
- -
-
-
- Method for synthesizing R-(+)-2-(4-hydroxyphenoxy)propionic acid through gas phase catalysis
-
The invention discloses a method for synthesizing R-(+)-2-(4-hydroxyphenoxy)propionic acid through gas phase catalysis, and belongs to the field of organic synthesis. Hydroquinone and D-lactic acid are used as raw materials, and nitrogen is used as a carrier gas. The hydroquinone and the D-lactic acid are completely gasified and then enter a fixed bed reactor, and the R-(+)-2-(4-hydroxyphenoxy)propionic acid is continuously synthesized in a gas phase under the catalysis of a supported heteropolyacid catalyst. The method has the advantages of mild reaction conditions, simple reaction process, high effective conversion rate of hydroquinone and high selectivity of the R-(+)-2-(4-hydroxyphenoxy) propionic acid, and is completely suitable for industrial production, and the self-made supported heteropolyacid solid catalyst has excellent catalytic activity, strong acidity, good stability and no pollution to the environment, and is a green catalyst.
- -
-
Paragraph 0015-0025
(2020/06/09)
-
- Preparation method for R-(+)-2-(4-hydroxyphenoxy)propionic acid
-
The invention discloses a preparation method for R-(+)-2-(4-hydroxyphenoxy)propionic acid. The method comprises the following steps: mixing phenol and S-2-chloropropionic acid or a salt of the S-2-chloropropionic acid, water and a first catalyst in a closed environment, and under the protection of an inert gas, performing heating and an alkylation reaction to prepare 2-phenoxypropionic acid; mixing the 2-phenoxypropionic acid, a second catalyst and a halogenating agent, and performing a reaction at 20-30 DEG C to prepare 2-(4-halogenated phenoxy)propionic acid; and performing a micro-pressurereaction on the 2-(4-halogenated phenoxy)propionic acid, an alkali solution and a third catalyst at 150-160 DEG C in a sealed environment, after the reaction is completed, performing filtration, and performing acidification treatment to obtain the R-(+)-2-(4-hydroxyphenoxy)propionic acid. The method provided by the invention uses the phenol and the organic acid or the organic acid salt as raw materials, and has simple purification and high purity of the product.
- -
-
Paragraph 0076-0078; 0087-0089
(2020/02/27)
-
- Herbicide composition containing metamifop and quinclorac
-
The invention discloses an herbicide composition containing metamifop and quinclorac. The herbicide composition comprises primary active ingredients and secondary active ingredients, wherein the primary active ingredients comprise the following components in parts by mass: 5-10 parts of metamifop and 10-20 parts of quinclorac; the secondary active ingredients are selected from the following components in parts by mass: 10-20 parts of cyhalofop-butyl, 3-8 parts of bispyribac-sodium, 1-6 parts of halosulfuron-methyl, 3-7 parts of pyrazosulfuron-ethyl and 6-10 parts of pyribenzoxim; and the secondary active ingredients refer to one of cyhalofop-butyl, bispyribac-sodium, halosulfuron-methyl, pyrazosulfuron-ethyl and pyribenzoxim. The invention relates to the technical field of herbicides. According to the herbicide composition containing metamifop and quinclorac disclosed by the invention, the problems such as herbicide resistant weed plants appearing, soil contamination, degradation of water, harm of non-weeds and the like are solved.
- -
-
Paragraph 0024; 0026; 0035; 0041; 0054
(2019/03/08)
-
- Method for synthesizing herbicide clodinafop-propargyl key intermediate
-
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.
- -
-
Paragraph 0041-0042
(2018/11/27)
-
- Preparation method of (R)-(+)-2-p-hydroxyl phenoxyl propionic acid
-
The invention relates to a preparation method of (R)-(+)-2-p-hydroxyl phenoxyl propionic acid. The method comprises the following steps of taking (S)-(-)-lactic acid as a raw material, and performingthree-step reaction, i.e., esterification, nucleophilic substitution and hydrolysis to obtain a target compound. A synthetic process for the (R)-(+)-2-p-hydroxyl phenoxyl propionic acid is further optimized, and the optimum reaction condition and reagent are screened. According to the preparation method designed in the invention, the reaction steps are shortened, and the yield and optical purity of the (R)-(+)-2-p-hydroxyl phenoxyl propionic acid are improved.
- -
-
Paragraph 0057; 0060
(2018/11/22)
-
- Method for preparing (R)-(+)-2-(4-hydroxyphenoxy) propionic acid in micro-structure reactor
-
The invention relates to the field of fine chemical engineering, in particular, a method for preparing (R)-(+)-2-(4-hydroxyphenoxy) propionic acid in a micro-structure reactor. The provided method utilizes a micro-structure reactor to prepare R)-(+)-DHPPA, overcomes the shortages of a conventional method, and has the following advantages: (1) the byproduct is few, and the yield is high; (2) the operation is simple, and continuous and controllable production is realized; and (3) according to the production needs, massive production can be realized, and there is no amplification effect.
- -
-
Paragraph 0028; 0031; 0032
(2018/06/21)
-
- Synthesis method of R-(+)-2-(4-hydroxyphenoxy) propionic acid
-
The invention discloses a synthesis method of R-(+)-2-(4-hydroxyphenoxy) propionic acid. The method comprises the following steps: (1), adding hydroquinone into a sodium hydroxide solution containingan organic solvent in batches, and performing reaction under in N2 atmosphere, so as to obtain p-hydroxy sodium phenate turbid liquid; (2), dissolving S-(-)-2-chloropropionic acid in an organic solvent, and slowly adding Na2CO3 solid in an ice-water bath condition to perform reaction, so as to obtain an S-(-)-2-sodium chloropropionic acid solution; (3), slowly dropwise adding the solution in the step (2) into the turbid liquid in the step (1), and performing reduced pressure distillation, dissolution and acidification, extraction and reduced pressure distillation on obtained reaction liquid, so as to obtain white solid, namely the R-(+)-2-(4-hydroxyphenoxy) propionic acid. The synthesis method has the advantages of simple synthesis route, mild reaction condition, high product yield, high product optical purity ee value, high recovery rate of hydroquinone, less produced three wastes and low energy consumption.
- -
-
Paragraph 0013; 0029-0050
(2018/08/03)
-
- Ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester, and preparation and applications thereof
-
The invention provides a weeding compound used for killing and preventing gramineous weeds in paddy fields. The weeding compound is ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester. A preparation method comprises following steps: hydroquinone and (S)-(-)-2-chloropropionic acid are subjected to Williamson etherification reaction at alkaline conditions so as to obtain (R)2-[4-hydroxy-phenoxy]propionic acid; reaction with a strong base is carried out so as to obtain (R)2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic acid; and reaction with a strong base is carried out so as to obtain ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester. The preparation method is simple; reaction is mild; no high temperature high pressure condition is needed; reaction time is relatively short; yield is high; the weeding compound can be used for killing Euphorbia lathyris with high efficiency, and can also be used for killing crab grass, paspalum distichum, green bristlegrass, eleusine indica, and alopecurus aequalis, and possesses excellent killing effect on barnyard grass with drug resistance; and the using amount is less than that of cyhalofop-butyl.
- -
-
Paragraph 0026; 0027; 0028; 0029
(2017/10/07)
-
- Optimization of the use of a chiral bio-based building block for the manufacture of DHPPA, a key intermediate for propionate herbicides
-
An alternative route for the production of (R)-2-(4-hydroxyphenoxy) propionic acid (DHPPA), a key intermediate in herbicide chemistry, is proposed. This route makes use of a chiral building block, initially produced by fermentation. The route has been optimized based on two steps: chlorination and etherification. The chlorination step has a maximum ee of 99% and a yield of 85% after distillation. The etherification step has a yield of 66%. Comparison of the route with the industrial standard shows a significant improvement in terms of green chemistry: waste streams are lowered up to 7-fold and the toxicity of the waste streams is reduced. This journal is the Partner Organisations 2014.
- Fleer, Michel P. M.,Verkuijl, Bastiaan J. V.
-
p. 3993 - 3998
(2014/08/05)
-
- Synthesis of dendrimer-type chiral stationary phases based on the selector of (1S,2R)-(+)-2-amino-1,2-diphenylethanol derivate and their enantioseparation evaluation by HPLC
-
In our recent work, a series of dendritic chiral stationary phases (CSPs) were synthesized, in which the chiral selector was L-2-(p-toluenesulfonamido)-3- phenylpropionyl chloride (selector I), and the CSP derived from three-generation dendrimer showed the best separation ability. To further investigate the influence of the structures of dendrimer and chiral selector on enantioseparation ability, in this work, another series CSPs (CSPs 1-4) were prepared by immobilizing (1S,2R)-1,2-diphenyl-2-(3-phenylureido)ethyl 4-isocyanatophenylcarbamate (selector II) on one- to four-generation dendrimers that were prepared in previous work. CSPs 1 and 4 demonstrated the equivalent enantioseparation ability. CSPs 2 and 3 showed the best and poorest enantioseparation ability respectively. Basically, these two series of CSPs exhibited the equivalent enantioseparation ability although the chiral selectors were different. Considering the enantioseparation ability of the CSP derived from aminated silica gel and selector II is much better than that of the one derived from aminated silica gel and selector I, it is believed that the dendrimer conformation essentially impacts enantioseparation.
- He, Bao-Jiang,Yin, Chuan-Qi,Li, Shi-Rong,Bai, Zheng-Wu
-
experimental part
p. 69 - 76
(2010/09/09)
-
- Regioselective preparation of (R)-2-(4-hydroxyphenoxy)propionic acid with a fungal peroxygenase
-
The extracellular heme-thiolate peroxygenase of Agrocybe aegerita catalyzed the H2O2-dependent hydroxylation of 2-phenoxypropionic acid (POPA) to give the herbicide precursor 2-(4-hydroxyphenoxy)propionic acid (HPOPA). The reaction proceeded regioselectively with an isomeric purity near 98%, and yielded the desired R-isomer of HPOPA with an enantiomeric excess of 60%. 18O-labeling experiments showed that the phenolic hydroxyl in HPOPA originated from H2O2, which establishes that the reaction is mechanistically a peroxygenation. Our results raise the possibility that fungal peroxygenases may be useful for a variety of organic oxidations.
- Kinne, Matthias,Ullrich, René,Hammel, Kenneth E.,Scheibner, Katrin,Hofrichter, Martin
-
body text
p. 5950 - 5953
(2009/04/04)
-
- A PROCESS FOR OPTICAL PURE (R)-2-PHENOXYPROPIONIC ACID DERIVATIVES
-
The present invention relates to a method for manufacturing optically active (R)-2-phenoxypropionic acid derivatives. More particularly, the present invention relates to a method for manufacturing optically active (R)-2-phenoxypropionic acid derivatives with high purity by using p-substituted phenol derivatives and alkyl (S)-2-arylsulfonyloxypropionate as starting materials and reacting them at 60 to 100 °C in the presence of an alkalimetal salt as a base and. a hydrocarbon solvent.
- -
-
Page/Page column 8
(2008/06/13)
-
- PRODUCTION PROCESS OF OPTICALLY PURE 2- (4-HYDROXYPHENOXY) - PROPIONIC ACID COMPOUNDS
-
A process for producing optically pure R-hydroxyphenoxypropanoic acid or a salt or ester thereof by reaction of hydroquinone or a salt thereof with an S-halopropanoic acid or a salt thereof in the presence of a mild reducing agent.
- -
-
Page/Page column 5
(2008/06/13)
-
- Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation
-
A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.
- Kato, Dai-Ichiro,Mitsuda, Satoshi,Ohta, Hiromichi
-
p. 7234 - 7242
(2007/10/03)
-
- Design, synthesis, and evaluation of postulated transient intermediate and substrate analogues as inhibitors of 4-hydroxyphenylpyruvate dioxygenase
-
An epoxybenzoquinone, 4-hydroxyphenoxypropionic acid, and 2-hydroxy-3-phenyl-3-butenoic acid derivatives have been designed, synthesized, and evaluated for in vitro inhibition activity against 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) from pig liver by the spectrophotometric enol-borate method. The biological data demonstrated that neither epoxybenzoquinone ester nor 2-hydroxy-3-phenyl-3-butenoic acid is an inhibitor of 4-HPPD. The most potent 4-HPPD inhibitor tested was 3-hydroxy-4-phenyl-2(5H)-furanone with an IC50 value of 0.5 μM, which may serve as a lead compound for further design of more potent 4-HPPD inhibitors.
- Lin, Yun-Loung,Huang, Jian-Lin,Wu, Chung-Shieh,Liu, Hung-Ge,Yang, Ding-Yah
-
p. 1709 - 1713
(2007/10/03)
-
- Preparation of mixtures of (R)- and (S)-2-(4-alkanoylphenoxy)- or (R)- and (S)-2-(4-aroylphenoxy)propionic esters
-
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.
- -
-
-
- (2-quinoxalinyloxy) phenoxypropanoic acids and related derivatives as anticancer agents
-
This invention relates to (2-quinoxalinyloxy)phenoxypropanoic acids, related derivatives thereof, enantiomeric and diastereomeric forms thereof, mixtures of enantiomeric diastereomeric forms thereof, and pharmaceutically acceptable salt forms thereof, pharmaceutical compositions containing them, processes for their preparation, and methods of using them to treat cancer, particularly solid tumors, in mammals.
- -
-
-
- Preparation of optically active α-(hydroxyphenoxy)alkanecarboxylic acids and derivatives thereof
-
Optically active α-(hydroxyphenoxy)-alkanecarboxylic acids or derivatives thereof, for example D-2-(4-hydroxyphenoxy)propionic acid or lower alkyl ester thereof, are prepared by (a) saponifying an alkyl ester of an optically active α-halogeno-alkanecarboxylic acid, in an alcoholic solvent medium, by reacting same with an aqueous solution of an alkali metal hydroxide, thereby providing a solution of an alkali metal salt of an optically active α-halogeno-alkanecarboxylic acid, (b) next reacting the step (a) solution thus provided with a dihydroxybenzene or salt thereof, in the presence of an alkali metal hydroxide and in an alcoholic solvent medium, and thence (c) recovering the optically active α-(hydroxyphenoxy)-alkanecarboxylic acid or derivative thereof from the medium of reaction.
- -
-
-
- Preparation of (R)-2-(4-Hydroxyphenoxy) propionic acid by biotransformation
-
With Beauveria bassiana Lu 700 as biocatalyst an ecologically beneficial process has been developed for the production of (R)-2-(4-hydroxyphenoxy) propionic acid. The fungal strain used in this process, B. bassiana Lu 700, is also a very suitable catalyst for the selective monohydroxylation of other aromatic carboxylic acids.
- Dingler, Christoph,Ladner, Wolfgang,Georg,Krei, Bryan Cooper,Hauerj, Bernhard
-
-
- Phenoxypropionic acid ester derivatives as herbicides
-
Disclosed is a novel compound of the formula [I]: STR1 wherein A represents STR2 (wherein X is H or Cl) STR3 Z represents STR4 (wherein R1 is H or CH3, R2 is H or C1 -C4 alkyl), furylmethyl group, tetrahydrofuryl group 2-tetrahydropyranylmethyl group or tetrahydrofurfuryl group which may be substituted with methyl group. The compound has strong herbicidal effect against the weeds belonging to the Family Gramineae.
- -
-
-
- Liquid crystal material
-
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.
- -
-
-
- Synthesis of 2-(4-hydroxyphenoxy)alkanoic acids
-
A method for synthesizing 2-(4-hydroxyphenoxy)alkanoic acids by reacting a hydroxyaromatic ketone derivative with a 2-substituted alkanoic acid under basic conditions and thereafter oxidizing the intermediate with subsequent hydrolysis.
- -
-
-
- Process for racemizing optically active alpha-phenoxypropionic acid and derivatives thereof
-
Optically active enantiomers of alkyl α-phenoxypropionates, and of derivatives thereof, can be racemized in good yields and without formation of decomposition products with the aid of an alkali metal (C1 -C5) alcoholate, an alkali metal hydroquinone, an alkali metal phenolate or an alkali metal hydroxyphenoxypropionate, or derivatives thereof.
- -
-
-
- Derivatives of (pyrimidyloxy)phenoxy-alkanecarboxylic acid and herbicidal compositions thereof
-
A compound of general formula I: STR1 wherein A, B, D, E, and V are independently chosen from hydrogen, halogen, nitro, cyano, thiocyano, amino, alkyl, alkoxy, alkylthio, alkenyl, cycloalkyl, carbalkoxy, phenyl, phenoxy or phenylthio; R1 and R2 are independently hydrogen, alkyl, alkenyl, alkanoyl, or R1 and R2 together are alkylidene; W is carboxy or a functional derivative thereof or CH2 Z wherein Z is halogen, hydroxy, alkoxy, alkylthio, formyl or amino; and X and Y are oxygen or sulfur.
- -
-
-