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Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid

A technology of hydroxyphenoxy and chlorophenoxy, applied in the field of electric power environmental protection, can solve the problems of difficult purification of products, large environmental pollution, low yield, etc., and achieve the effect of low price and simple process operation

Pending Publication Date: 2021-04-20
锦州四海生物化学有限公司
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Problems solved by technology

[0005] (2) EP0180126 discloses the synthesis of L-methyl p-toluenesulfonyl lactate with L-methyl lactate and p-toluenesulfonyl chloride, and then reacts with hydroquinone. During the reaction, the configuration is reversed to obtain DHPPA. The optical purity of the product of this method is Poor, the e.e value is only 90-95%, and the by-product p-toluenesulfonic acid is difficult to recover in the waste water, and the environmental pollution is relatively large
[0007] (3) US4489207 discloses the one-step synthesis of DHPPA by reacting hydroquinone with (S)-(-)-2-chloropropionic acid. This method produces a large amount of waste water that is difficult to treat due to the reaction in alkaline aqueous solution, and DHPPA It has a certain solubility in water, and some products cannot be recovered after being dissolved in water, so the yield is also low
[0009] The above methods are all using hydroquinone as a raw material, which will inevitably produce hydroquinone double-substituted impurities (content accounts for 10-20wt%, structural formula such as formula (4)), resulting in difficult purification of the product and unguaranteed product quality

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  • Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid
  • Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid
  • Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid

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[0028] The invention provides a method for preparing (R)-(+)-2-(4-hydroxyphenoxy)propionic acid, comprising the following steps:

[0029] Condensation reaction of phenolic compound and (S)-(-)-2-halopropionic acid under basic conditions to obtain R-(+)-2-(4-chlorophenoxy)propionic acid; the Phenolic compounds are p-chlorophenol, p-bromophenol, p-iodophenol or p-hydroxybenzenesulfonic acid;

[0030] The R-(+)-2-(4-chlorophenoxy)propionic acid is hydrolyzed under the catalysis of a catalyst to obtain the (R)-(+)-2-(4-hydroxyphenoxy ) Propionic acid.

[0031] In the present invention, unless otherwise specified, the raw materials used are commercially available products in the art.

[0032] In the present invention, phenolic compounds and (S)-(-)-2-halopropionic acid are condensed under alkaline conditions to obtain R-(+)-2-(4-chlorophenoxy)propionic acid; The phenolic compound is p-chlorophenol, p-bromophenol, p-iodophenol or p-hydroxybenzenesulfonic acid.

[0033] In the pr...

Embodiment 1

[0057] (1) Synthesis of R-(+)-2-(4-chlorophenoxy)propionic acid: Add 128.6g of p-chlorophenol, 200mL of 30% mass concentration sodium hydroxide aqueous solution in a 1L four-necked bottle, and heat up to Stir at 50°C for 30min, add 108.5g of (S)-(-)-2-chloropropionic acid dropwise, keep the reaction at 50°C for 2 hours, and perform liquid phase detection (Shimadzu liquid chromatography, detection condition: C18 chromatographic column, wavelength 230nm , column temperature 30°C, mobile phase acetonitrile and water volume ratio = 15:85) raw material p-chlorophenol HPLC area normalized content < 0.3%, concentrated hydrochloric acid to adjust pH = 1, filter off-white solid R-(+)- 200.2 g of 2-(4-chlorophenoxy)propionic acid (water content 10wt% by Karl Fischer test), liquid phase content (area normalized content) = 97.4%, directly proceed to the next step without drying.

[0058] (2) Synthesis of R-(+)-2-(4-hydroxyphenoxy)propionic acid: add 200.2 R-(+)-2-(4-chlorophenoxy)propioni...

Embodiment 2

[0064] (1) Synthesis of R-(+)-2-(4-chlorophenoxy)propionic acid: 128.6g of p-chlorophenol was added in a 1L four-necked bottle, 200mL of 35% mass concentration sodium hydroxide aqueous solution was heated to Stir at 60°C for 30min, add 108.5g of (S)-(-)-2-chloropropionic acid dropwise, keep the reaction at 60°C for 2 hours, and perform liquid phase detection (Shimadzu liquid chromatograph, detection condition: C18 chromatographic column, wavelength 230nm , column temperature 30°C, mobile phase acetonitrile and water volume ratio = 15:85) raw material p-chlorophenol HPLC area normalized content < 0.3%, concentrated hydrochloric acid to adjust pH = 1, filter off-white solid R-(+)- 200.8g of 2-(4-chlorophenoxy)propionic acid (water content 10wt% by Karl Fischer test), liquid phase content (area normalized content) = 97.2%, directly proceed to the next step without drying.

[0065] (2) Synthesis of R-(+)-2-(4-hydroxyphenoxy)propionic acid: add 200.8 R-(+)-2-(4-chlorophenoxy)propio...

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Abstract

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.

Description

technical field [0001] The invention relates to the technical field of electric power environmental protection, in particular to a preparation method of (R)-(+)-2-(4-hydroxyphenoxy)propionic acid. Background technique [0002] Aryloxypropionic acid herbicides are a new type of optically active herbicides, which have the characteristics of high efficiency and low toxicity, wide herbicidal spectrum, high selectivity, easy biodegradation, long application period and safety to crops. Among them, R-(+)-2-(4-hydroxyphenoxy)propionic acid (abbreviation: DHPPA, white or off-white crystal, CAS No. 94050-90-5, molecular formula C 9 h 10 o 4 , molecular weight 182.17, melting point 145 ~ 148 ° C) is a synthetic thiazoprop-methyl, high-efficiency fluroxyfop, chloralifop-pyl, quizalofop-p-ethyl, clodinafop-propargyl, huma, high-efficiency gaitrafop and cyanofluoride It is an important intermediate of dozens of aryloxypropionic acid herbicides such as grass ester, so the synthesis of D...

Claims

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Application Information

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IPC IPC(8): C07C51/367C07C51/347C07C59/68
Inventor 王栋伟赵宏洋王诚刘涛
Owner 锦州四海生物化学有限公司
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