Loctofen preparation method

A technology for the preparation of lactoferin and lactoferin, which is applied in the field of the preparation of lactoferin-ethyl raw medicine, to achieve the effects of high content of the original medicine, reduction of by-product formation, and high yield

Active Publication Date: 2009-02-11
QINGDAO HANSEN BIOLOGIC SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a method for preparing lactofen-alifop TC, which solves the problem of suppressing side reactions in the synthesis process of lactofen-prop-methyl TC, and improves the formation of the target product.

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0037] 1) Preparation of 3-[2-chloro-4-(trifluoromethyl)phenoxy]benzoic acid

[0038] In a 100L reactor, add 38.60Kg dimethyl sulfoxide (99%, 490mol) and put it into the reactor after metering, and add 10.10Kg potassium hydroxide (93%, 168mol) and 10.45Kg m-hydroxybenzene while stirring Formic acid (98%, 74.2 mol) was heated to 110° C. for a salt-forming reaction for 3 hours, and the water and part of the solvent generated by the reaction were removed under reduced pressure. Then add 3.45Kg anhydrous potassium carbonate (98%, 24.5mol) and 15.28Kg 3.4-dichlorobenzotrifluoride (98.5%, 70mol) in still, continue to heat up to 152-158 ℃, carry out condensation reaction, condensation reaction 20 -22 hours, the solvent dimethyl sulfoxide was removed. Add water to dissolve the remaining solids in the kettle, add concentrated hydrochloric acid dropwise to the solution for acidification to make PH=1-2, after the acidification is completed, carry out centrifugation, dry the wet product ...

Embodiment 2

[0045] 1) Preparation of 3-[2-chloro-4-(trifluoromethyl)phenoxy]benzoic acid

[0046] In a 100L reactor, add 38.60Kg dimethyl sulfoxide (99%, 490mol) and put it into the reactor after metering, and add 10.10Kg potassium hydroxide (93%, 168mol) and 10.45Kg m-hydroxybenzene while stirring Formic acid (98%, 74.2 mol) was heated to 110° C. for a salt-forming reaction for 3 hours, and the water and part of the solvent generated by the reaction were removed under reduced pressure. Then add 3.45Kg anhydrous potassium carbonate (98%, 24.5mol) and 15.28Kg 3.4-dichlorobenzotrifluoride (98.5%, 70mol) in still, continue to heat up to 152-158 ℃, carry out condensation reaction, condensation reaction 20 -22 hours, the solvent dimethyl sulfoxide was removed. Add water to dissolve the remaining solids in the tank, add concentrated hydrochloric acid dropwise to the solution for acidification to make PH = 1-2, after the acidification is completed, perform centrifugation, and dry the cake to ob...

Embodiment 3

[0053] Repeat the same steps as described in Example 1, but from step 3): the preparation of lactofen: in a 100L reactor, add 73.25Kg ethyl 2-chloropropionate (99%, 530mol), 19.86Kg 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (91.0%, 50mol) was added under stirring, and the temperature was raised to 80-85°C to obtain solution A. In a 150L reactor, add 43.95Kg ethyl 2-chloropropionate (99%, 320mol) and 9.15Kg potassium carbonate (99%, 65mol), stir and heat up at 80-85°C to obtain solution B, and at 80-85°C, dissolve A Add the solution dropwise into solution B. After the dropwise addition, heat up to 90-95°C and add 0.2Kg tetrabutylammonium bromide, then keep it warm at 90-95°C for 6-8 hours, measure the reaction end point by HPLC, filter, and add water to the filtrate Wash with water until neutral, remove the water layer, remove excess ethyl 2-chloropropionate from the oil layer to obtain 24.4Kg of lactofen-alifop, with a content of 87.3%, and a yield of 92.3%, ...

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Abstract

The invention relates to a preparation method of Lactofen technical product of pesticides, belonging to the technical field of fluorine-containing diphenyl ether pesticide. 3,4-dichloro (trifluoromethyl) benzene and m-hydroxybenzoic acid are used as starting materials. After salification, condensation, acidification and nitrification processes, acifluorfen-sodium that is the intermediate product is produced. Acifluorfen-sodium and ethyl 2-chloropropionate are condensed into Lactofen technical product of pesticides under the action of catalyzer. The invention is characterized in that the catalyzer is quaternary ammonium salt and the dosage is within the range 5 permil to 10 permil. The method of the invention has the advantages of high yield, high content of technical product of pesticides, cheap and available raw material and easy realization in industry.

Description

technical field [0001] The invention belongs to the technical field of fluorine-containing diphenyl ether pesticides, and in particular relates to a method for preparing lactoforin as an active drug. Background technique [0002] Lactofen (lactofen) is also known as Kekuole, and its chemical name is O-[5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoyl-DL lactate ethyl ester , is a fluorine-containing diphenyl ether herbicide, is a protoporphyrinogen oxidase inhibitor, and is a high-efficiency, low-toxicity, broad-spectrum upland herbicide. Inside the cell, it destroys the cell membrane, causing the contents of the cell to overflow, causing physical damage to the plant tissue, and eventually leading to death. Lactoforin is mainly used in soybean, peanut, cotton, rice, grape and other crop fields to control annual broad-leaved weeds such as cocklebur, nightshade, ragweed, datura, purslane, iron Amaranth etc. The research on lactoforin in my country began in the 1990s, an...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/59C07C201/12
Inventor 李树柏刘瑞宾吴本林郭前坤
Owner QINGDAO HANSEN BIOLOGIC SCI
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