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Ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester, and preparation and applications thereof

A technology of fluorophenoxy and phenoxy, which is applied in the field of ethyl-2-[4--phenoxy]propionate and its preparation and application, can solve the problems of ineffectiveness, and achieve simple process and long reaction time , the effect of less dosage

Inactive Publication Date: 2017-09-22
燕化永乐(乐亭)生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the dosage of cyhalofop-fop-methyl on D. chinensis has been increased from the initial 75-150g ai / hm2 to 225-450g ai / hm2, and cyhalofop-ethyl is ineffective against some resistant D. chinensis

Method used

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  • Ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester, and preparation and applications thereof
  • Ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester, and preparation and applications thereof
  • Ethyl(2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy]propionic ester, and preparation and applications thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Example 1 Synthesis of (R) 2-[4-hydroxy-phenoxy] propionic acid

[0027]

[0028] At room temperature, hydroquinone (60 g, 544.90 mmol) and (S)-(-)-2-chloropropionic acid (10.3 g, 94.91 mmol) were added to 134 g of NaOH solution with a concentration of 15% by mass. The temperature of the system was raised to reflux, and after 3 hours, gas chromatography detected that the reaction was complete. After cooling, the ice bath is reduced to 0°C, and dilute hydrochloric acid is added dropwise to pH=6.0. After the methyl isobutyl ketone was extracted, the aqueous phase was acidified to pH = 1.0, the system became turbid, and the methyl isobutyl ketone was extracted twice with 100 ml each time. The organic phase was distilled to dryness under reduced pressure, and the residue was vacuum dried to constant weight at 40°C to obtain a brown solid. Recrystallize with water, wash the wet product with cold water, and dry under reduced pressure at 60°C to a constant weight to obtain 10.8...

Embodiment 2

[0030] Example 2 Synthesis of (R)2-[4-(4-cyano-2-fluorophenoxy)-phenoxy]propionic acid

[0031]

[0032] Add (R) 2-[4-hydroxy-phenoxy] propionic acid (10.0 g, 54.89 mmol) and potassium carbonate (8.0 g, 57.31 mmol) to 100 ml of acetonitrile, and stir at room temperature for 30 minutes. Add 3,4-difluorobenzonitrile (9g, 64.70mmol), heat to reflux, keep for 6 hours, high performance liquid chromatography detects that the reaction is complete. The temperature was lowered to room temperature, 250ml of water was added, and it was extracted twice with ethyl acetate, each time of 50ml. Cool the water layer in an ice bath to 0°C, add dilute hydrochloric acid solution dropwise to pH 3-4, and solids will gradually precipitate out. Keep the temperature at 0-10°C and continue to stir for 1 hour, filter, and wash the filter cake with 50ml cold water twice, 50°C vacuum After drying to constant weight, 13.5 g (content 96%) of a white solid, namely (R) 2-[4-(4-cyano 2-fluorophenoxy)-phenoxy] pr...

Embodiment 3

[0034] Example 3 Synthesis of ethyl (2R)-2-[4-(4-cyano-2-fluorophenoxy)-phenoxy]propionate

[0035]

[0036] To 150ml of N,N-dimethylformamide, add (R)2-[4-(4-cyano-2-fluorophenoxy)-phenoxy]propionic acid (13.5g, 96%, 43.02mmol), Potassium hydroxide (2.64g, 45.17mmol), 1ml water, stirred for 30min. The temperature of the system was raised to 40° C., and 20 ml of N,N-dimethylformamide solution of bromoethane (7.0 g, 64.53 mmol) was added dropwise. Maintain this temperature, react for 3 hours, and high performance liquid chromatography detects that the reaction is complete. Warm up to 60℃, add 150ml of water dropwise, then hot filter, filter cake is washed with water, ice ethanol, and vacuum dried at 45℃ to constant weight to obtain 12.0g (99%) off-white solid, namely ethyl (2R)-2 -[4-(4-Cyano-2-fluorophenoxy)-phenoxy]propionate. The yield was 83.9%.

[0037] 1 H-NMR(DMSO-D 6 )δ:1.18(3H,t,J=7.0Hz),δ:1.51(3H,d,J=6.8Hz),δ:4.15(2H,m,J=7.0Hz),δ:4.96(1H,q ,J=6.8Hz),δ:6.96(1H,dd,J=1.6...

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Abstract

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.

Description

Technical field [0001] The invention belongs to the field of chemical pesticides, and specifically relates to an ethyl (2R)-2-[4-(4-cyano 2-fluorophenoxy)-phenoxy] propionate and its preparation and application. Background technique [0002] Due to the development of science and technology and the rise of labor costs, the use of herbicides has become more and more frequent, and people are gradually relying on herbicides. The unreasonable use of most of the existing herbicides puts a strong selective pressure on weeds, and the resistance of weeds is becoming stronger and stronger. The use of chemical herbicides has led to the continuous enhancement of weed resistance, and the rational development and utilization of herbicides has become increasingly severe. [0003] Cyhalofop-butyl, whose chemical name is (R)-2-[4(4-cyano-2-fluorophenoxy)phenoxy]-butyl propionate, is the only herbicide of aryloxyphenoxypropionic acid Varieties with high safety to rice, like other varieties in this...

Claims

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Application Information

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IPC IPC(8): A01N39/04C07C253/30C07C255/54C07C51/367C07C51/41C07C59/70A01P13/00
CPCA01N39/04C07B2200/07C07C51/367C07C51/412C07C253/30C07C59/70C07C255/54
Inventor 杨会营刘晓娇张连举
Owner 燕化永乐(乐亭)生物科技有限公司
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