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Preparation method of halauxifen-methyl

A technology for fluorochloropyridine ester and dichloropyridine, which is applied in the field of preparation of fluorochloropyridine ester, can solve the problems of unobtainable raw materials, unsuitability for industrial production and the like, and achieves the effects of high reaction efficiency, shortened production cycle and mild reaction conditions

Active Publication Date: 2021-11-05
ZHEJIANG AVILIVE CHEM CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the yield of these two steps is high, the raw material of methyl 4-acetylamino-3,6-dichloropyridine-2-carboxylate is not easy to obtain
Literature (Bioorganic & Medicinal Chemistry, 2016,24(3):362-371.) reported that 4-acetylamino-3,6-dichloropyridine-2-carboxylic acid methyl ester is 4-amino-3,6-dichloropyridine -2-Formic acid is obtained by heating methanol to reflux for 24 hours, and then acetic anhydride is heated and refluxed for 16 hours. Among them, acetic anhydride is subject to control as a precursor to drug production. The total yield of this route is 27.20%, which is not suitable for industrial production

Method used

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  • Preparation method of halauxifen-methyl
  • Preparation method of halauxifen-methyl
  • Preparation method of halauxifen-methyl

Examples

Experimental program
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Effect test

Embodiment 1

[0039] (1) Preparation of 4-amino-3,6-dichloropyridine-2-carboxylic acid methyl ester (III)

[0040]Add 4-amino-3,6-dichloropyridine-2-carboxylic acid (II) (5.00g, 24.15mmol) into a 100mL eggplant-shaped bottle, add 20mL methanol, stir to dissolve, and drop Thionyl chloride (5.75g, 48.31mmol) was added. After the addition was complete, the reaction was carried out at 60°C. The solution gradually became clear and stirred for 7 hours. The reaction was complete as monitored by TLC. The heating was stopped, cooled to room temperature, and the solvent was evaporated under reduced pressure. Adjust the pH to 9 with 25-28% ammonia water at -5-0°C to precipitate a powdery white solid, filter it with suction, wash with water (30mL×3), and dry to obtain 4.98g of a pink solid, with a yield of 93.26%.

[0041] 1 H-NMR (300MHz, DMSO-d 6 ),δ(ppm):7.10(s,2H,-NH 2 ),6.83(s,1H,-ArH),3.89(s,3H,-CH 3 ).

[0042] (2) Preparation of 4-(N,N-diamido)-3,6-dichloropyridine-2-carboxylic acid methyl...

Embodiment 2

[0052] (1) Preparation of 4-amino-3,6-dichloropyridine-2-carboxylic acid methyl ester (III)

[0053] Add 4-amino-3,6-dichloropyridine-2-carboxylic acid (II) (5.00g, 24.15mmol) into a 100mL eggplant-shaped bottle, add 20mL methanol, stir to dissolve, and drop Add concentrated sulfuric acid (1.54mL), move to react at 60°C after dropping, the solution gradually clarifies, stir and react for about 7 hours, TLC monitors that the reaction is complete, stop heating, cool to room temperature, evaporate the solvent under reduced pressure, and store at -5~0°C The pH was adjusted to 9 with 25-28% ammonia water, and a powdery white solid was precipitated, filtered with suction, washed with water (30mL×3), and dried to obtain 4.76g of a pink solid, with a yield of 89.14%.

[0054] (2) Preparation of 4-(N,N-diamido)-3,6-dichloropyridine-2-carboxylic acid methyl ester (IV)

[0055] Add intermediate III (2.00g, 9.05mmol) into a 25mL eggplant-shaped flask, add 10mL of acetonitrile, stir to di...

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Abstract

The invention discloses a preparation method of halauxifen-methyl, namely 4-amino-3-chloro-6-(2-fluoro-4-chloro-3-methoxyphenyl) pyridine-2-formic acid methyl ester, according to the method, the 4-amino-3, 6-dichloropyridine-2-formic acid methyl ester is used as a raw material, and the halauxifen-methyl is obtained through the steps of amino protection, coupling and deprotection, the amino protection reagent is a protection reagent sensitive to acidic conditions. According to the preparation method, raw materials are easy to obtain, special production equipment is not needed, the reaction yield of each step reaches 70% or above, aftertreatment is simple and convenient, the product purity is 99% or above, and the preparation method is more suitable for industrial production.

Description

technical field [0001] The present invention relates to a preparation method of halfenapyridine ester, in particular to a preparation method of halhalopyridine ester which is easy to operate and excellent in product yield and purity. Background technique [0002] HalauxIfen-methyl (I), the chemical name is 4-amino-3-chloro-6-(2-fluoro-4-chloro-3-methoxyphenyl)pyridine-2-methyl carboxylate, The CAS accession number is: 943831-98-9. Haclopyridin is the first synthetic auxin herbicide with aryl picolinate structure developed by Dow AgroSciences. The ISO generic name of the active ingredient was approved in November 2012. On April 10, 2014, Dow AgroSciences’ two products, 93% fluclopyridine technical and 20% bisfluorochlorofluridine water dispersible granules, obtained provisional registration from the Drug Control Institute of the Ministry of Agriculture. Nong Yi Rui Huo TM (fluclopyrxate) and sharp supermilk TM (10% haclopyridine + 10% florasulam) is the trade name and it ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/79C07D213/803
CPCC07D213/79C07D213/803Y02P20/55
Inventor 朱启华陈琳雅李兰杰李惠跃张灵芝赵能选徐云根
Owner ZHEJIANG AVILIVE CHEM CO LTD
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