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A method for preparing (r)-(+)-2-(4-hydroxyphenoxy acid) propionic acid in a microstructure reactor

A technology of microstructure reactor and hydroxyphenoxy acid, which is applied in chemical instruments and methods, preparation of carboxylic acid esters, organic chemical methods, etc., can solve the problems of high price, high loss, complicated operation, etc., and achieve no amplification effect , less by-products, simple operation

Active Publication Date: 2019-07-05
HUAIAN GUORUI CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The synthetic method of bibliographical report R-(+)-DHPPA mainly contains: (1) obtain the ester of racemization with hydroquinone and α-bromo propionate reaction, carry out resolution again, obtain R-(+) -DHPPA, the raw materials of this route are more expensive, the reaction time is long, and the total yield is low (WO8200639); (2) the reaction of S-(-)-2-ethyl p-toluenesulfonyl lactate and hydroquinone can obtain the structure Type overturned R-(+)-DHPPA ethyl ester, yield 70%-80%, although this reaction yield is higher, final product will be purified with column chromatography, is difficult to reach the requirement of suitability for industrialized production (US5886209; Weng Jianquan etc. Journal of Zhejiang University of Technology, 2009,37(4):362.); (3) Using p-hydroxyacetophenone as the starting material, reacting with α-halogenated propionate, oxidizing and hydrolyzing to obtain external elimination Spin DHPPA, and obtain target compound R-(+)-DHPPA through resolution again, yield 48.2%, this method is complicated to operate, and step is long, and loss is more, and the used raw material and resolution reagent price are more expensive, and production High cost, not suitable for industrial production (EP0334596)

Method used

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  • A method for preparing (r)-(+)-2-(4-hydroxyphenoxy acid) propionic acid in a microstructure reactor
  • A method for preparing (r)-(+)-2-(4-hydroxyphenoxy acid) propionic acid in a microstructure reactor
  • A method for preparing (r)-(+)-2-(4-hydroxyphenoxy acid) propionic acid in a microstructure reactor

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Effect test

Embodiment 1

[0024] (1) Synthesis of α-hydroxypropionate methyl ester

[0025] Methyl L-lactate was transported into microstructure reactor W1 by advection pump A1 at a flow rate of 0.2 mL / min; dissolving pyridine in thionyl chloride was transported into microstructure reactor W1 by advection pump A2 at a flow rate of 0.152 mL / min ; The two are mixed and reacted at 20° C. for 1 min before entering step (2); in step (2), the molar ratio of L-lactate methyl ester, thionyl chloride and pyridine is 1:1:0.005. After the reaction was finished, samples were taken, and analyzed by GC, the conversion rate of methyl L-lactate was 100%, and the yield of methyl α-hydroxypropionate was 98%.

[0026] (2) Synthesis of (R)-(+)-DHPPA

[0027] Hydroquinone and sodium hydroxide (30%) are transported into the microstructure reactor W2 through the advection pumps A3 and A4 respectively, mixed with the reaction solution obtained in step (1), and reacted at 30° C. for 0.5 min before entering the collection tank...

Embodiment 2

[0029] (1) Synthesis of ethyl α-hydroxypropionate

[0030] L-ethyl lactate was transported into microstructure reactor W1 by advection pump A1 at a flow rate of 1mL / min; 3,5-lutidine was dissolved in thionyl chloride and transported into microstructure reactor W1 by advection pump A2. The flow rate is 0.87 mL / min; after mixing, react at 30°C for 1.5 min and enter step (2). In step (1), the molar ratio of L-ethyl lactate, thionyl chloride and 3,5-lutidine is 1:1.2:0.01. After the reaction was finished, samples were taken, and analyzed by GC, the conversion rate of ethyl L-lactate was 100%, and the yield of ethyl α-hydroxypropionate was 98.6%.

[0031] (2) Synthesis of (R)-(+)-DHPPA

[0032] Hydroquinone and potassium hydroxide (30%) are transported into the microstructure reactor W2 through the advection pumps A3 and A4 respectively, mixed with the reaction solution from step (1), reacted at 20°C for 1.5min and then collected Can. In step (2), the flow rate of hydroquinone ...

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Abstract

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.

Description

technical field [0001] The invention relates to the field of fine chemicals, in particular to a method for preparing (R)-(+)-2-(4-hydroxyphenoxy acid)propionic acid in a microstructure reactor. Background technique [0002] As early as the 1970s, it was discovered that aryloxypropionic acid herbicides are a new class of optically active herbicides, which have the advantages of high efficiency and low toxicity, wide herbicidal spectrum, high selectivity, easy biodegradation, and safety to crops. Dozens of varieties have been published (Xia Xiangdong et al. Journal of Pesticide Science, 2013, 15(6): 609.; Nie Wenyan. Sichuan Chemical Industry, 2011, 14(4): 21.). 2-(4-Hydroxyphenoxyacid) propionic acid (DHPPA) is a synthetic compound of dozens of products such as thiaprop-prop, haloxyfop-methyl, clodinafop-propargyl, quizalofop-p, cyhalofop-p-methyl and high-efficiency gaizafen An important intermediate of an aryloxypropionic acid herbicide. In particular, the R-configuration...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C59/125C07C51/09C07C67/31C07C69/708C07C67/307C07C69/63
CPCC07B2200/07C07C51/09C07C67/307C07C67/31C07C69/63C07C69/708C07C59/125
Inventor 李明陈超钟钰王凤云张璞陈明光毛更生
Owner HUAIAN GUORUI CHEM CO LTD